diff --git a/server/routers/knowledge_router.py b/server/routers/knowledge_router.py
index 782be605..a52bfe9a 100644
--- a/server/routers/knowledge_router.py
+++ b/server/routers/knowledge_router.py
@@ -411,8 +411,16 @@ async def delete_document(db_id: str, doc_id: str, current_user: User = Depends(
     try:
         file_meta_info = await knowledge_base.get_file_basic_info(db_id, doc_id)
         file_name = file_meta_info.get("meta", {}).get("filename")
-        minio_client = get_minio_client()
-        await minio_client.adelete_file("ref-" + db_id.replace("_", "-"), file_name)
+
+        # 尝试从MinIO删除文件，如果失败（例如旧知识库没有MinIO实例），则忽略
+        try:
+            minio_client = get_minio_client()
+            await minio_client.adelete_file("ref-" + db_id.replace("_", "-"), file_name)
+            logger.debug(f"成功从MinIO删除文件: {file_name}")
+        except Exception as minio_error:
+            logger.warning(f"从MinIO删除文件失败（可能是旧知识库）: {minio_error}")
+
+        # 无论MinIO删除是否成功，都继续从知识库删除
         await knowledge_base.delete_file(db_id, doc_id)
         return {"message": "删除成功"}
     except Exception as e: