diff --git a/packages/adapters/sqlalchemy_impl/workspace_member_repository.py b/packages/adapters/sqlalchemy_impl/workspace_member_repository.py
index dcaac543c..ef0f3551b 100644
--- a/packages/adapters/sqlalchemy_impl/workspace_member_repository.py
+++ b/packages/adapters/sqlalchemy_impl/workspace_member_repository.py
@@ -1,11 +1,16 @@
 from __future__ import annotations
 
-from sqlalchemy.orm import Session
+from typing import List, Optional, TYPE_CHECKING
+
+from sqlalchemy.orm import Session, joinedload
 
 from packages.adapters.sqlalchemy_impl.models import WorkspaceMemberModel
 from packages.domain.entities import WorkspaceMember
 from packages.ports.workspace_member_repository import WorkspaceMemberRepository
 
+if TYPE_CHECKING:
+    from packages.adapters.sqlalchemy_impl.models import UserModel
+
 
 class SQLAlchemyWorkspaceMemberRepository(WorkspaceMemberRepository):
     def __init__(self, session: Session):
@@ -56,9 +61,15 @@ class SQLAlchemyWorkspaceMemberRepository(WorkspaceMemberRepository):
         return [self._to_entity(model) for model in models if model is not None]
 
     def find_by_workspace(self, workspace_id: str) -> list[WorkspaceMember]:
+        """查找 workspace 的所有成员，使用 JOIN 预加载用户数据避免 N+1 查询问题。
+        
+        P2-3 Fix: 使用 joinedload 预加载关联的用户数据，
+        这样在访问 member.user 时不会触发额外的数据库查询。
+        """
         models = (
             self.session.query(WorkspaceMemberModel)
             .filter(WorkspaceMemberModel.workspace_id == workspace_id)
+            .options(joinedload(WorkspaceMemberModel.user))  # P2-3: JOIN 预加载用户数据
             .order_by(WorkspaceMemberModel.joined_at.asc())
             .all()
         )