diff --git a/backend/common/schema.py b/backend/common/schema.py
index b64da0b2..1e0d3400 100644
--- a/backend/common/schema.py
+++ b/backend/common/schema.py
@@ -37,8 +37,10 @@ class SchemaBase(BaseModel):
 
         # 详情：https://fastapi-practices.github.io/fastapi_best_architecture_docs/backend/reference/pk.html#%E6%B3%A8%E6%84%8F%E4%BA%8B%E9%A1%B9
         @field_serializer('id', check_fields=False)
-        def serialize_id(self, value: int) -> str:
-            return str(value)
+        def serialize_id(self, value: int) -> str | int:
+            if self.model_config.get('from_attributes'):
+                return str(value)
+            return value
 
 
 def ser_string(value: Any) -> str | None: