diff --git a/backend/apps/system/models/system_model.py b/backend/apps/system/models/system_model.py
index 73fa3443..e2536e6b 100644
--- a/backend/apps/system/models/system_model.py
+++ b/backend/apps/system/models/system_model.py
@@ -14,8 +14,8 @@ class AiModelBase:
 
 class AiModelDetail(SnowflakeBase, AiModelBase, table=True):
    __tablename__ = "ai_model"
-   api_key: str | None = Field(nullable=True)
-   api_domain: str = Field(nullable=False)
+   api_key: str | None = Field(default=None, nullable=True, sa_type=Text())
+   api_domain: str = Field(nullable=False, sa_type=Text())
    protocol: int = Field(nullable=False, default = 1)
    config: str = Field(sa_type = Text())
    status: int = Field(nullable=False, default = 1)