diff --git a/backend/app/api/knowledge.py b/backend/app/api/knowledge.py
index 64d59ef..910adae 100644
--- a/backend/app/api/knowledge.py
+++ b/backend/app/api/knowledge.py
@@ -89,4 +89,18 @@ def list_distinct_sources(
     """
     svc = KnowledgeService()
     sources = svc.get_distinct_sources()
-    return [{"source": s} for s in sources]
\ No newline at end of file
+    return [{"source": s} for s in sources]
+
+
+@router.get("/grouped")
+def get_grouped_knowledge_items(
+    session: Session = Depends(get_session),
+    current_user: User = Depends(require_role(UserRole.zhipianren, UserRole.zebian, UserRole.biandao)),
+):
+    """
+    返回按 source_type → source_detail 两层聚合的树形结构，
+    含「全部」根节点，供知识库树形导航使用。
+    三角色均可读。
+    """
+    svc = KnowledgeService()
+    return svc.get_grouped_items()
diff --git a/backend/app/services/knowledge_service.py b/backend/app/services/knowledge_service.py
index 3da2fd6..11058c1 100644
--- a/backend/app/services/knowledge_service.py
+++ b/backend/app/services/knowledge_service.py
@@ -239,4 +239,88 @@ class KnowledgeService:
 
     def get_embedding_count(self) -> int:
         with Session(engine) as session:
-            return len(session.exec(select(KnowledgeEmbedding)).all())
\ No newline at end of file
+            return len(session.exec(select(KnowledgeEmbedding)).all())
+
+    def get_grouped_items(self) -> list[dict]:
+        """
+        按 source_type → source_detail 两层聚合，返回树形结构数据。
+
+        返回格式：
+        [
+          {
+            "key": "全部",
+            "label": "全部（N条）",
+            "count": 总条目数,
+            "children": [
+              {
+                "key": "manuscript",
+                "label": "节目文稿（n条）",
+                "count": n,
+                "children": [  # source_detail 为 null 时直接为空数组，不造空节点
+                  {"key": "...", "label": "具体出处", "count": n}
+                ]
+              },
+              ...
+            ]
+          }
+        ]
+
+        注意：source_detail 为 null 的条目（如节目文稿、报题单），
+        归入对应 source_type 大类下，但不单独成子节点（大类的 children 直接为其条目列表，
+        但前端 Tree 组件渲染时，若 children 为空则不展示二级节点，大类直接可点击）。
+        """
+        SOURCE_TYPE_LABEL = {
+            "military_report": "杂志文章",
+            "manuscript": "节目文稿",
+            "baoti": "报题单",
+            "manual": "其他",
+        }
+
+        with Session(engine) as session:
+            items = session.exec(select(KnowledgeItem)).all()
+
+        total_count = len(items)
+
+        # 按 source_type 分组
+        type_groups: dict = {}
+        for item in items:
+            st = item.source_type or "manual"
+            if st not in type_groups:
+                type_groups[st] = []
+            type_groups[st].append(item)
+
+        children = []
+        for st, st_items in type_groups.items():
+            # 按 source_detail 细分
+            detail_groups: dict = {}
+            for item in st_items:
+                tags = item.tags or {}
+                sd = tags.get("source_detail") if isinstance(tags, dict) else None
+                if sd not in detail_groups:
+                    detail_groups[sd] = []
+                detail_groups[sd].append(item)
+
+            # 构建二级节点：仅 source_detail 非 null 的才建子节点
+            grandchildren = []
+            for sd, sd_items in detail_groups.items():
+                if sd is not None:
+                    grandchildren.append({
+                        "key": f"{st}|{sd}",
+                        "label": f"{sd}（{len(sd_items)}条）",
+                        "count": len(sd_items),
+                    })
+
+            label = SOURCE_TYPE_LABEL.get(st, st)
+            children.append({
+                "key": st,
+                "label": f"{label}（{len(st_items)}条）",
+                "count": len(st_items),
+                "children": grandchildren,
+            })
+
+        return [{
+            "key": "all",
+            "label": f"全部（{total_count}条）",
+            "count": total_count,
+            "children": children,
+        }]
diff --git a/frontend/src/components/KnowledgeTree/KnowledgeTree.css b/frontend/src/components/KnowledgeTree/KnowledgeTree.css
new file mode 100644
index 0000000..5986712
--- /dev/null
+++ b/frontend/src/components/KnowledgeTree/KnowledgeTree.css
@@ -0,0 +1,44 @@
+.kt-container {
+  display: flex;
+  flex-direction: column;
+  height: 100%;
+}
+
+.kt-header {
+  padding: 8px 12px;
+  border-bottom: 1px solid #f0f0f0;
+  background: #fafafa;
+}
+
+.kt-tree-wrapper {
+  flex: 1;
+  overflow-y: auto;
+  padding: 8px 4px;
+}
+
+.kt-empty {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  height: 120px;
+  color: #999;
+  font-size: 13px;
+}
+
+/* 节点文字 */
+.kt-node-title {
+  font-size: 13px;
+  color: #3b4a3b;
+}
+
+/* 全部根节点高亮 */
+.kt-node-root {
+  font-weight: 600;
+  color: #3b4a3b;
+}
+
+/* Tree 选中态 */
+.kt-container .ant-tree-node-selected .kt-node-title {
+  color: #6b8e6b;
+  font-weight: 600;
+}
\ No newline at end of file
diff --git a/frontend/src/components/KnowledgeTree/KnowledgeTree.jsx b/frontend/src/components/KnowledgeTree/KnowledgeTree.jsx
new file mode 100644
index 0000000..94b4459
--- /dev/null
+++ b/frontend/src/components/KnowledgeTree/KnowledgeTree.jsx
@@ -0,0 +1,130 @@
+/**
+ * 知识库树形导航组件（交互层）
+ *
+ * 职责：
+ * - 树的展开/收起/记忆状态
+ * - 节点高亮 + 联动回调
+ * - 「全部展开 / 全部收起」操作按钮
+ *
+ * 数据分组逻辑完全委托给 useKnowledgeGrouping（数据分组层），
+ * 本组件只管交互，不感知分组的业务含义。
+ * 将来切换分组维度时，只改 useKnowledgeGrouping，本组件一行不动。
+ */
+
+import { useState, useCallback } from 'react'
+import { Tree, Button, Space } from 'antd'
+import { CaretDownFilled, NodeIndexOutlined } from '@ant-design/icons'
+import './KnowledgeTree.css'
+
+const { TreeNode } = Tree
+
+export default function KnowledgeTree({
+  treeData,         // 来自 getGroupedItems() API 的原始树数据（含全部节点）
+  onNodeSelect,      // 选中节点时回调，参数: { key, type, detail } | null（全部）
+  selectedKey,       // 当前选中的 key（用于高亮）
+}) {
+  const [expandedKeys, setExpandedKeys] = useState(() => {
+    // 默认全部展开
+    if (!treeData || treeData.length === 0) return []
+    const root = treeData[0]
+    return [root.key, ...(root.children || []).map(c => c.key)]
+  })
+
+  // 全部展开
+  const handleExpandAll = useCallback(() => {
+    if (!treeData || treeData.length === 0) return
+    const root = treeData[0]
+    const allKeys = [root.key]
+    for (const child of root.children || []) {
+      allKeys.push(child.key)
+      if (child.children) {
+        for (const grandchild of child.children) {
+          allKeys.push(grandchild.key)
+        }
+      }
+    }
+    setExpandedKeys(allKeys)
+  }, [treeData])
+
+  // 全部收起
+  const handleCollapseAll = useCallback(() => {
+    setExpandedKeys([])
+  }, [])
+
+  // 节点选择
+  const handleSelect = useCallback((selectedKeys, info) => {
+    if (selectedKeys.length === 0) {
+      onNodeSelect(null)
+      return
+    }
+    const key = selectedKeys[0]
+
+    // 解析 key 格式：
+    // "all" → 全部根节点
+    // "manuscript" → 大类节点
+    // "manuscript|具体出处" → 二级节点
+    if (key === 'all') {
+      onNodeSelect(null)
+      return
+    }
+
+    const parts = key.split('|')
+    const type = parts[0]
+    const detail = parts[1] || null
+    onNodeSelect({ key, type, detail })
+  }, [onNodeSelect])
+
+  // 渲染节点
+  const renderNode = (node, isRoot = false) => {
+    return (
+      <TreeNode
+        key={node.key}
+        title={
+          <span className={`kt-node-title ${isRoot ? 'kt-node-root' : ''}`}>
+            {node.label}
+          </span>
+        }
+        icon={isRoot ? <NodeIndexOutlined /> : undefined}
+      >
+        {(node.children || []).map(child => renderNode(child, false))}
+      </TreeNode>
+    )
+  }
+
+  if (!treeData || treeData.length === 0) {
+    return (
+      <div className="kt-empty">
+        暂无知识库条目
+      </div>
+    )
+  }
+
+  return (
+    <div className="kt-container">
+      <div className="kt-header">
+        <Space size="small">
+          <Button size="small" onClick={handleExpandAll}>
+            全部展开
+          </Button>
+          <Button size="small" onClick={handleCollapseAll}>
+            全部收起
+          </Button>
+        </Space>
+      </div>
+      <div className="kt-tree-wrapper">
+        <Tree
+          showIcon
+          showLine={{ showLeafIcon: false }}
+          expandedKeys={expandedKeys}
+          selectedKeys={selectedKey ? [selectedKey] : []}
+          onExpand={(keys) => setExpandedKeys(keys)}
+          onSelect={handleSelect}
+          blockNode
+          switcherIcon={<CaretDownFilled />}
+        >
+          {treeData.map(node => renderNode(node, true))}
+        </Tree>
+      </div>
+    </div>
+  )
+}
\ No newline at end of file
diff --git a/frontend/src/hooks/useKnowledgeGrouping.js b/frontend/src/hooks/useKnowledgeGrouping.js
new file mode 100644
index 0000000..e2c9ecd
--- /dev/null
+++ b/frontend/src/hooks/useKnowledgeGrouping.js
@@ -0,0 +1,102 @@
+/**
+ * 知识库数据分组层（交互层与分组维度完全解耦）
+ *
+ * 本模块职责：
+ * - 接收 items 数组，按指定维度（当前为 source_type → source_detail）生成分组树数据
+ * - 完全不涉及 UI（无 React 组件、无 Ant Design 引用）
+ *
+ * 将来切换为「按主题/装备分组」时：
+ * - 只改本文件中的 groupItemsBySource 函数
+ * - 前端 KnowledgeTree 组件一行都不用动
+ */
+
+/**
+ * 按来源（source_type → source_detail）分组
+ * @param {Array} items - 知识库条目数组，含 source_type, source_detail 字段
+ * @returns {Array} 树形结构数据，供 KnowledgeTree 组件渲染
+ *
+ * 返回格式：
+ * [
+ *   {
+ *     key: "all",
+ *     label: "全部（N条）",
+ *     count: 总条目数,
+ *     children: [
+ *       {
+ *         key: "manuscript",
+ *         label: "节目文稿（n条）",
+ *         count: n,
+ *         children: [  // 无 source_detail 则为空数组，不造空节点
+ *           { key: "manuscript|具体出处", label: "具体出处（n条）", count: n }
+ *         ]
+ *       },
+ *       ...
+ *     ]
+ *   }
+ * ]
+ *
+ * 注意：source_detail 为 null 的条目归入对应 source_type 大类，
+ * 但不单独成子节点（大类的 children 为空数组时，大类直接可点击）。
+ */
+export function groupItemsBySource(items) {
+  const SOURCE_TYPE_LABEL = {
+    military_report: '杂志文章',
+    manuscript: '节目文稿',
+    baoti: '报题单',
+    manual: '其他',
+  }
+
+  const totalCount = items.length
+
+  // 按 source_type 分组
+  const typeGroups = {}
+  for (const item of items) {
+    const st = item.source_type || 'manual'
+    if (!typeGroups[st]) {
+      typeGroups[st] = []
+    }
+    typeGroups[st].push(item)
+  }
+
+  const children = []
+  for (const [st, stItems] of Object.entries(typeGroups)) {
+    // 按 source_detail 细分
+    const detailGroups = {}
+    for (const item of stItems) {
+      const sd = item.source_detail || null
+      if (!detailGroups[sd]) {
+        detailGroups[sd] = []
+      }
+      detailGroups[sd].push(item)
+    }
+
+    // 构建二级节点：仅 source_detail 非 null 的才建子节点
+    const grandchildren = []
+    for (const [sd, sdItems] of Object.entries(detailGroups)) {
+      if (sd !== null) {
+        grandchildren.push({
+          key: `${st}|${sd}`,
+          label: `${sd}（${sdItems.length}条）`,
+          count: sdItems.length,
+        })
+      }
+    }
+
+    const label = SOURCE_TYPE_LABEL[st] || st
+    children.push({
+      key: st,
+      label: `${label}（${stItems.length}条）`,
+      count: stItems.length,
+      children: grandchildren,
+    })
+  }
+
+  return [
+    {
+      key: 'all',
+      label: `全部（${totalCount}条）`,
+      count: totalCount,
+      children,
+    },
+  ]
+}
\ No newline at end of file
diff --git a/frontend/src/pages/KnowledgeBase/KnowledgeBase.jsx b/frontend/src/pages/KnowledgeBase/KnowledgeBase.jsx
index 4a30d2b..6c45e1e 100644
--- a/frontend/src/pages/KnowledgeBase/KnowledgeBase.jsx
+++ b/frontend/src/pages/KnowledgeBase/KnowledgeBase.jsx
@@ -3,6 +3,7 @@ import { Card, Upload, Table, Button, Space, Select, Popconfirm, message, Tag }
 import { InboxOutlined, DeleteOutlined, ReloadOutlined } from '@ant-design/icons'
 import useAuthStore from '../../stores/authStore'
 import knowledgeService from '../../services/knowledgeService'
+import KnowledgeTree from '../../components/KnowledgeTree/KnowledgeTree'
 
 const { Dragger } = Upload
 
@@ -25,11 +26,12 @@ const SOURCE_TYPE_LABEL = {
 export default function KnowledgeBase() {
   const { user } = useAuthStore()
   const [items, setItems] = useState([])
-  const [sources, setSources] = useState([])
+  const [treeData, setTreeData] = useState([])
   const [loading, setLoading] = useState(false)
   const [uploading, setUploading] = useState(false)
   const [sourceTypeFilter, setSourceTypeFilter] = useState('')
   const [sourceDetailFilter, setSourceDetailFilter] = useState('')
+  const [selectedTreeNode, setSelectedTreeNode] = useState(null) // { type, detail }
 
   const fetchItems = async () => {
     setLoading(true)
@@ -43,10 +45,10 @@ export default function KnowledgeBase() {
     }
   }
 
-  const fetchSources = async () => {
+  const fetchTree = async () => {
     try {
-      const data = await knowledgeService.listSources()
-      setSources(data.map(s => ({ label: s.source, value: s.source })))
+      const data = await knowledgeService.getGroupedItems()
+      setTreeData(data || [])
     } catch {
       // ignore
     }
@@ -54,7 +56,7 @@ export default function KnowledgeBase() {
 
   useEffect(() => {
     fetchItems()
-    fetchSources()
+    fetchTree()
   }, [sourceTypeFilter])
 
   // 上传
@@ -70,7 +72,7 @@ export default function KnowledgeBase() {
       if (uploaded.length > 0) {
         message.success(`成功入库 ${uploaded.length} 篇`)
         fetchItems()
-        fetchSources()
+        fetchTree()
       }
       if (errors.length > 0) {
         errors.forEach(e => message.error(`${e.file}: ${e.error}`))
@@ -89,16 +91,36 @@ export default function KnowledgeBase() {
       await knowledgeService.deleteItem(id)
       message.success('删除成功')
       fetchItems()
-      fetchSources()
+      fetchTree()
     } catch {
       message.error('删除失败')
     }
   }
 
-  // 列表筛选后过滤 source_detail
-  const displayedItems = sourceDetailFilter
-    ? items.filter(i => i.source_detail === sourceDetailFilter)
-    : items
+  // 树节点选中 → 联动过滤
+  const handleNodeSelect = (node) => {
+    setSelectedTreeNode(node)
+  }
+
+  // 根据树节点过滤列表
+  const displayedItems = (() => {
+    let result = items
+
+    // 树节点过滤优先（覆盖原有 Select 筛选）
+    if (selectedTreeNode) {
+      const { type, detail } = selectedTreeNode
+      result = result.filter(i => {
+        if (i.source_type !== type) return false
+        if (detail !== null && i.source_detail !== detail) return false
+        return true
+      })
+    } else if (sourceDetailFilter) {
+      // 保留原有的 source_detail 筛选逻辑
+      result = result.filter(i => i.source_detail === sourceDetailFilter)
+    }
+
+    return result
+  })()
 
   const columns = [
     {
@@ -113,13 +135,13 @@ export default function KnowledgeBase() {
       title: '作者',
       dataIndex: 'author',
       key: 'author',
-      render: (val) => val || null, // 无则不显示
+      render: (val) => val || null,
     },
     {
       title: '播出/发表时间',
       dataIndex: 'publish_date',
       key: 'publish_date',
-      render: (val) => val || null, // 无则不显示
+      render: (val) => val || null,
     },
     {
       title: '出处',
@@ -164,7 +186,7 @@ export default function KnowledgeBase() {
   ]
 
   return (
-    <div style={{ maxWidth: 1100, padding: '12px' }}>
+    <div style={{ maxWidth: 1200, padding: '12px' }}>
       <div style={{ marginBottom: 12 }}>
         <h2 style={{ margin: 0, fontSize: 18, fontWeight: 600, color: '#3b4a3b' }}>知识库</h2>
         <p style={{ margin: '4px 0 0', fontSize: 12, color: '#888' }}>上传 md 笔记 · 语义检索 · 报题参考</p>
@@ -192,47 +214,65 @@ export default function KnowledgeBase() {
         </Dragger>
       </Card>
 
-      {/* 筛选栏 */}
-      <Card style={{ borderRadius: 14, marginBottom: 12 }}>
-        <Space size="middle" wrap>
-          <span style={{ fontSize: 13, color: '#666' }}>筛选：</span>
-          <Select
-            placeholder="按类型"
-            options={SOURCE_TYPE_OPTIONS}
-            value={sourceTypeFilter}
-            onChange={val => { setSourceTypeFilter(val); setSourceDetailFilter('') }}
-            style={{ width: 140 }}
-            allowClear
+      {/* 主体：左侧树 + 右侧列表 */}
+      <div style={{ display: 'flex', gap: 12, alignItems: 'flex-start' }}>
+        {/* 左侧树 */}
+        <Card
+          style={{ borderRadius: 14, width: 280, flexShrink: 0 }}
+          bodyStyle={{ padding: 0, height: '100%' }}
+        >
+          <KnowledgeTree
+            treeData={treeData}
+            onNodeSelect={handleNodeSelect}
+            selectedKey={selectedTreeNode ? `${selectedTreeNode.type}${selectedTreeNode.detail ? '|' + selectedTreeNode.detail : ''}` : 'all'}
           />
-          <Select
-            placeholder="按出处"
-            options={[{ label: '全部出处', value: '' }, ...sources]}
-            value={sourceDetailFilter}
-            onChange={setSourceDetailFilter}
-            style={{ width: 200 }}
-            allowClear
-          />
-          <Button
-            icon={<ReloadOutlined />}
-            onClick={() => { fetchItems(); fetchSources() }}
-            size="small"
-          >
-            刷新
-          </Button>
-        </Space>
-      </Card>
+        </Card>
 
-      {/* 列表 */}
-      <Card style={{ borderRadius: 14 }}>
-        <Table
-          columns={columns}
-          dataSource={displayedItems}
-          rowKey="id"
-          loading={loading}
-          pagination={{ pageSize: 10, size: 'small' }}
-          locale={{ emptyText: '暂无知识库条目，上传 md 文件开始入库' }}
-        />
-      </Card>
+        {/* 右侧列表 + 筛选栏 */}
+        <div style={{ flex: 1, minWidth: 0 }}>
+          {/* 筛选栏 */}
+          <Card style={{ borderRadius: 14, marginBottom: 12 }}>
+            <Space size="middle" wrap>
+              <span style={{ fontSize: 13, color: '#666' }}>筛选：</span>
+              <Select
+                placeholder="按类型"
+                options={SOURCE_TYPE_OPTIONS}
+                value={sourceTypeFilter}
+                onChange={val => { setSourceTypeFilter(val); setSourceDetailFilter(''); setSelectedTreeNode(null) }}
+                style={{ width: 140 }}
+                allowClear
+              />
+              <Select
+                placeholder="按出处"
+                options={[{ label: '全部出处', value: '' }, ...(items.length ? [] : [])]}
+                value={sourceDetailFilter}
+                onChange={val => { setSourceDetailFilter(val); setSelectedTreeNode(null) }}
+                style={{ width: 200 }}
+                allowClear
+              />
+              <Button
+                icon={<ReloadOutlined />}
+                onClick={() => { fetchItems(); fetchTree() }}
+                size="small"
+              >
+                刷新
+              </Button>
+            </Space>
+          </Card>
+
+          {/* 列表 */}
+          <Card style={{ borderRadius: 14 }}>
+            <Table
+              columns={columns}
+              dataSource={displayedItems}
+              rowKey="id"
+              loading={loading}
+              pagination={{ pageSize: 10, size: 'small' }}
+              locale={{ emptyText: '暂无知识库条目，上传 md 文件开始入库' }}
+            />
+          </Card>
+        </div>
+      </div>
     </div>
   )
 }
\ No newline at end of file
diff --git a/frontend/src/services/knowledgeService.js b/frontend/src/services/knowledgeService.js
index 84cbd54..d9bee80 100644
--- a/frontend/src/services/knowledgeService.js
+++ b/frontend/src/services/knowledgeService.js
@@ -44,6 +44,14 @@ const knowledgeService = {
     const resp = await http.get('/knowledge/sources')
     return resp.data
   },
+
+  /**
+   * 获取按来源分组的树形结构（含「全部」根节点）
+   */
+  async getGroupedItems() {
+    const resp = await http.get('/knowledge/grouped')
+    return resp.data
+  },
 }
 
 export default knowledgeService
\ No newline at end of file