diff --git a/video-gen-api/app/api/v1/admin.py b/video-gen-api/app/api/v1/admin.py
index 9ffe1331..113b9c79 100644
--- a/video-gen-api/app/api/v1/admin.py
+++ b/video-gen-api/app/api/v1/admin.py
@@ -1856,10 +1856,12 @@ async def get_stats(
         )
     )).scalar() or 0
 
-    # ── 每日各模块积分消耗（按日期+模块分组，子查询排序避免 PG GROUP BY 限制）
-    _daily_subq = (
+    # ── 每日各模块积分消耗（按日期+模块分组）
+    from sqlalchemy import Date, cast as sa_cast
+    _day_expr = sa_cast(CreditRecord.created_at, Date)
+    daily_credits_rows = (await db.execute(
         select(
-            func.to_char(CreditRecord.created_at, 'YYYY-MM-DD').label('date'),
+            _day_expr.label('date'),
             func.coalesce(CreditRecord.source_module, 'other').label('module'),
             func.coalesce(func.sum(func.abs(CreditRecord.amount)), 0).label('credits'),
         )
@@ -1868,15 +1870,11 @@ async def get_stats(
             CreditRecord.created_at >= date_start,
             CreditRecord.created_at <= date_end,
         )
-        .group_by(func.to_char(CreditRecord.created_at, 'YYYY-MM-DD'), func.coalesce(CreditRecord.source_module, 'other'))
-        .subquery()
-    )
-    daily_credits_rows = (await db.execute(
-        select(_daily_subq.c.date, _daily_subq.c.module, _daily_subq.c.credits)
-        .order_by(_daily_subq.c.date)
+        .group_by(_day_expr, func.coalesce(CreditRecord.source_module, 'other'))
+        .order_by(_day_expr)
     )).all()
     daily_credits_by_module = [
-        DailyCreditOut(date=row.date, module=row.module, credits=float(row.credits or 0))
+        DailyCreditOut(date=str(row.date), module=row.module, credits=float(row.credits or 0))
         for row in daily_credits_rows
     ]