diff --git a/internal/rpc/group/group.go b/internal/rpc/group/group.go
index 064448432..2b1f2224d 100644
--- a/internal/rpc/group/group.go
+++ b/internal/rpc/group/group.go
@@ -1821,6 +1821,8 @@ func (s *groupServer) SetGroupMemberInfo(ctx context.Context, req *pbGroup.SetGr
 	}
 	if req.Ex != nil {
 		m["ex"] = req.Ex.Value
+	} else {
+		m["ex"] = ""
 	}
 	err = imdb.UpdateGroupMemberInfoByMap(groupMember, m)
 	if err != nil {