diff --git a/api/migrations/versions/74b51dfece29_20260311000.py b/api/migrations/versions/74b51dfece29_20260311000.py
new file mode 100644
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+++ b/api/migrations/versions/74b51dfece29_20260311000.py
@@ -0,0 +1,156 @@
+"""20260311000
+
+Revision ID: 74b51dfece29
+Revises: f017efe4831c
+Create Date: 2026-03-19 10:15:42.488027
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = '74b51dfece29'
+down_revision: Union[str, None] = 'f017efe4831c'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # 先删除旧的触发器（如果存在）
+    op.execute("DROP TRIGGER IF EXISTS tr_documents_update_stats ON documents;")
+
+    # 创建或更新 knowledges 统计信息的函数
+    op.execute("""
+CREATE OR REPLACE FUNCTION update_knowledge_stats()
+RETURNS TRIGGER AS $$
+DECLARE
+    -- 声明变量用于存储当前处理的知识库ID
+    current_kb_id UUID;
+    -- 声明变量用于存储文件夹知识库ID（如果存在）
+    folder_kb_id UUID;
+    -- 声明变量用于存储递归查询结果
+    folder_ids UUID[];
+BEGIN
+    -- 处理 documents 表的插入、更新或删除
+    IF TG_TABLE_NAME = 'documents' THEN
+        -- 1. 更新 knowledges 表的 doc_num
+        UPDATE knowledges SET doc_num = (
+            SELECT COUNT(*) FROM documents
+            WHERE kb_id = knowledges.id AND status = 1
+        )
+        WHERE id = NEW.kb_id OR id = OLD.kb_id;
+
+        -- 2. 更新 knowledges 表的 chunk_num
+        UPDATE knowledges SET chunk_num = (
+            SELECT COALESCE(SUM(chunk_num), 0) FROM documents
+            WHERE kb_id = knowledges.id AND status = 1
+        )
+        WHERE id = NEW.kb_id OR id = OLD.kb_id;
+
+        -- 通过 knowledge_shares 表同步统计信息
+        -- 1. 使用 source_kb_id 的 doc_num 更新 target_kb_id 的 doc_num
+        UPDATE knowledges AS target
+        SET doc_num = source.doc_num
+        FROM knowledge_shares ks
+        JOIN knowledges AS source ON source.id = ks.source_kb_id
+        WHERE ks.target_kb_id = target.id
+          AND (source.id = NEW.kb_id OR source.id = OLD.kb_id);
+
+        -- 2. 使用 source_kb_id 的 chunk_num 更新 target_kb_id 的 chunk_num
+        UPDATE knowledges AS target
+        SET chunk_num = source.chunk_num
+        FROM knowledge_shares ks
+        JOIN knowledges AS source ON source.id = ks.source_kb_id
+        WHERE ks.target_kb_id = target.id
+          AND (source.id = NEW.kb_id OR source.id = OLD.kb_id);
+
+        -- 处理文件夹知识库的统计更新
+        -- 获取当前处理的知识库ID（可能是NEW或OLD中的kb_id）
+        IF NEW.kb_id IS NOT NULL THEN
+            current_kb_id := NEW.kb_id;
+        ELSIF OLD.kb_id IS NOT NULL THEN
+            current_kb_id := OLD.kb_id;
+        ELSE
+            RETURN NULL;
+        END IF;
+
+        -- 查找当前知识库的父文件夹（如果有）
+        SELECT id INTO folder_kb_id FROM knowledges
+        WHERE id IN (
+            SELECT parent_id FROM knowledges WHERE id = current_kb_id
+        ) AND type = 'Folder';
+
+        -- 如果存在父文件夹，递归处理所有父文件夹
+        IF folder_kb_id IS NOT NULL THEN
+            -- 使用递归CTE获取所有父文件夹ID（包括多级嵌套）
+            WITH RECURSIVE folder_hierarchy AS (
+                -- 基础查询：获取直接父文件夹
+                SELECT id FROM knowledges
+                WHERE id = folder_kb_id AND type = 'Folder'
+                UNION ALL
+                -- 递归查询：获取父文件夹的父文件夹
+                SELECT k.id FROM knowledges k
+                JOIN folder_hierarchy fh ON k.id = k.parent_id
+                WHERE k.type = 'Folder'
+            )
+            -- 将结果存入数组以便处理
+            SELECT array_agg(id) INTO folder_ids FROM folder_hierarchy;
+
+            -- 遍历所有父文件夹并更新统计信息
+            FOR i IN 1..array_length(folder_ids, 1) LOOP
+                -- 更新文件夹的doc_num（汇总所有子知识库的doc_num）
+                UPDATE knowledges SET doc_num = (
+                    -- 汇总直接子知识库的doc_num
+                    SELECT COALESCE(SUM(child.doc_num), 0)
+                    FROM knowledges child
+                    WHERE child.parent_id = folder_ids[i] AND child.status = 1
+                    -- 加上直接属于该文件夹的文档数（如果有）
+                    UNION ALL
+                    SELECT COALESCE(COUNT(*), 0)
+                    FROM documents
+                    WHERE kb_id = folder_ids[i] AND status = 1
+                    LIMIT 1
+                )
+                WHERE id = folder_ids[i];
+
+                -- 更新文件夹的chunk_num（汇总所有子知识库的chunk_num）
+                UPDATE knowledges SET chunk_num = (
+                    -- 汇总直接子知识库的chunk_num
+                    SELECT COALESCE(SUM(child.chunk_num), 0)
+                    FROM knowledges child
+                    WHERE child.parent_id = folder_ids[i] AND child.status = 1
+                    -- 加上直接属于该文件夹的文档的chunk_num（如果有）
+                    UNION ALL
+                    SELECT COALESCE(SUM(d.chunk_num), 0)
+                    FROM documents d
+                    WHERE d.kb_id = folder_ids[i] AND d.status = 1
+                    LIMIT 1
+                )
+                WHERE id = folder_ids[i];
+            END LOOP;
+        END IF;
+    END IF;
+
+    RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+    """)
+
+    # documents 表上的触发器（插入、更新、删除后）
+    op.execute("""
+CREATE TRIGGER tr_documents_update_stats
+    AFTER INSERT OR UPDATE OR DELETE ON documents
+    FOR EACH ROW
+    EXECUTE FUNCTION update_knowledge_stats();
+    """)
+
+
+def downgrade() -> None:
+    # 删除触发器
+    op.execute("DROP TRIGGER IF EXISTS tr_documents_update_stats ON documents;")
+    # 删除函数
+    op.execute("DROP FUNCTION IF EXISTS update_knowledge_stats();")
+