diff --git a/saas/backend/api/management/v2/serializers.py b/saas/backend/api/management/v2/serializers.py
index 19a222065..eaad5f30b 100644
--- a/saas/backend/api/management/v2/serializers.py
+++ b/saas/backend/api/management/v2/serializers.py
@@ -167,6 +167,7 @@ class ManagementGroupMemberSLZ(serializers.Serializer):
     id = serializers.CharField(label="成员id")
     name = serializers.CharField(label="名称")
     expired_at = serializers.IntegerField(label="过期时间戳(单位秒)")
+    created_at = serializers.IntegerField(label="创建时间戳(单位秒)")
 
 
 class ManagementGroupMemberDeleteSLZ(serializers.Serializer):
diff --git a/saas/backend/api/management/v2/views/group.py b/saas/backend/api/management/v2/views/group.py
index 2e0801901..3f948eaa5 100644
--- a/saas/backend/api/management/v2/views/group.py
+++ b/saas/backend/api/management/v2/views/group.py
@@ -362,7 +362,9 @@ def list(self, request, *args, **kwargs):
         limit, offset = CompatiblePagination().get_limit_offset_pair(request)
 
         count, group_members = self.biz.list_paging_thin_group_member(group.id, limit, offset)
-        results = [one.dict(include={"type", "id", "name", "expired_at"}) for one in group_members]
+        results = [one.dict(include={"type", "id", "name", "expired_at", "created_time"}) for one in group_members]
+        for result in results:
+            result['created_at'] = int(result.pop('created_time').timestamp())
         return Response({"count": count, "results": results})
 
     @swagger_auto_schema(
diff --git a/saas/backend/util/time.py b/saas/backend/util/time.py
index ed53eeba1..d61d854d9 100644
--- a/saas/backend/util/time.py
+++ b/saas/backend/util/time.py
@@ -33,8 +33,11 @@ def utc_string_to_timestamp(str_time: str) -> int:
     """
     后端UTC时间转换为时间戳
     """
-    t = string_to_datetime(str_time, fmt="%Y-%m-%dT%H:%M:%SZ")
-    return int(t.timestamp())
+    # Note: 该转换后是 naive datetime，即不带时区
+    naive_t = string_to_datetime(str_time, fmt="%Y-%m-%dT%H:%M:%SZ")
+    # 由于 str_time 本身就是 utc 时间字符串，所以可以设置时区为 UTC，这样就得到 aware datetime
+    aware_t = naive_t.replace(tzinfo=datetime.timezone.utc)
+    return int(aware_t.timestamp())
 
 
 def utc_to_local(utc_time):
diff --git a/saas/tests/util/time_tests.py b/saas/tests/util/time_tests.py
new file mode 100644
index 000000000..11cc8c463
--- /dev/null
+++ b/saas/tests/util/time_tests.py
@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+"""
+TencentBlueKing is pleased to support the open source community by making 蓝鲸智云-权限中心(BlueKing-IAM) available.
+Copyright (C) 2017-2021 THL A29 Limited, a Tencent company. All rights reserved.
+Licensed under the MIT License (the "License"); you may not use this file except in compliance with the License.
+You may obtain a copy of the License at http://opensource.org/licenses/MIT
+Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+specific language governing permissions and limitations under the License.
+"""
+import pytest
+
+from backend.util.time import utc_string_to_timestamp
+
+
+@pytest.mark.parametrize(
+    "utc_string, expected",
+    [
+        ("2025-01-07T08:41:18Z", 1736239278),
+        ("2025-01-07T09:03:44Z", 1736240624),
+        ("2025-01-02T10:00:15Z", 1735812015),
+        ("2025-01-08T03:42:02Z", 1736307722),
+    ],
+)
+def test_utc_string_to_timestamp(utc_string: str, expected: int):
+    assert utc_string_to_timestamp(utc_string) == expected