diff --git a/doco/src/doco/video_split.py b/doco/src/doco/video_split.py
index 7f73b0f..ede3b3a 100644
--- a/doco/src/doco/video_split.py
+++ b/doco/src/doco/video_split.py
@@ -543,10 +543,11 @@ def split_video(
         debug_csv=debug_csv_path,
     )
 
-    # 统计各 decision
+    # 统计各 decision（frame_analysis 已包含所有非空白帧的 decision）
     for frame_idx, data in frame_analysis.items():
         decision_stats[data["decision"]] = decision_stats.get(data["decision"], 0)
 
+    # 从 frame_analysis 统计中取 duplicate 相关计数（blank_count 已在上方单独统计）
     duplicate_iou = decision_stats.get("duplicate(iou)", 0)
     duplicate_hash = decision_stats.get("duplicate(hash)", 0)
     total_duplicate = blank_count + duplicate_iou + duplicate_hash
@@ -555,11 +556,25 @@ def split_video(
     print(f"[video_split] 检测到 {len(keyframes)} 个关键帧")
     print(f"[video_split] 诊断CSV写入: {debug_csv_path}")
 
-    # 确认 frames/ 目录文件数与 total_extracted 一致
+    # ---- 删除非关键帧,只保留最终关键帧 PNG ----
+    # 建立应保留的帧索引集合
+    keyframe_indices = set(kf["frame_index"] for kf in keyframes)
+    all_frame_files = sorted(frames_dir.glob("frame_*.png"))
+    deleted_count = 0
+    for frame_file in all_frame_files:
+        # 从文件名 frame_0001.png 提取帧索引
+        frame_idx = int(frame_file.stem.split("_")[1])
+        if frame_idx not in keyframe_indices:
+            frame_file.unlink()
+            deleted_count += 1
+
+    print(f"[video_split] 清理非关键帧完成,删除 {deleted_count} 张,保留 {len(keyframes)} 张关键帧")
+
+    # 确认 frames/ 目录文件数与关键帧数一致
     actual_frame_files = len(list(frames_dir.glob("frame_*.png")))
-    print(f"[debug] frames/ 目录实际文件数: {actual_frame_files} (预期: {total_extracted})")
-    if actual_frame_files != total_extracted:
-        print(f"[WARNING] frames/ 文件数({actual_frame_files}) 与抽帧数({total_extracted})不一致!")
+    print(f"[debug] frames/ 目录实际文件数: {actual_frame_files} (预期: {len(keyframes)})")
+    if actual_frame_files != len(keyframes):
+        print(f"[WARNING] frames/ 文件数({actual_frame_files}) 与关键帧数({len(keyframes)})不一致!")
 
     if dry_run:
         print("[video_split] dry-run:跳过 OCR")