diff --git a/app/models/workspace.py b/app/models/workspace.py
index 20d4986..0935c7c 100644
--- a/app/models/workspace.py
+++ b/app/models/workspace.py
@@ -1,7 +1,11 @@
+from typing import TYPE_CHECKING
 from sqlalchemy import Column, DateTime, String, ForeignKey, BigInteger, UniqueConstraint
 from sqlalchemy.sql import func
 from .base import AutoID, Base
 
+if TYPE_CHECKING:
+    from .user import User
+
 class Workspace(Base, AutoID):
     """工作区表"""
     __tablename__ = "workspaces"
@@ -24,11 +28,18 @@ class WorkspaceMember(Base, AutoID):
     """工作区成员及权限表"""
     __tablename__ = "workspace_members"
 
-    workspace_id = Column(String(32), ForeignKey("workspaces.id", ondelete="CASCADE"), index=True)
-    user_id = Column(String(32), ForeignKey("users.id", ondelete="CASCADE"), index=True)
-
+    workspace_id = Column(
+        String(Workspace.id_length()),
+        ForeignKey("workspaces.id", ondelete="CASCADE"),
+        index=True,
+    )
     # 允许 user_id 为空，因为被邀请的人可能还没注册系统，我们先记录他的邮箱
-    user_id = Column(String(32), ForeignKey("users.id", ondelete="CASCADE"), nullable=True, index=True)
+    user_id = Column(
+        String(User.id_length()),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=True,
+        index=True,
+    )
     invite_email = Column(String, nullable=True) # 收到邀请的邮箱
     
     # 状态：'pending' (等待加入), 'active' (已加入), 'disabled' (已禁用)