diff --git a/offline-backend-20260512/backend/packages/harness/deerflow/agents/memory/providers/hindsight.py b/offline-backend-20260512/backend/packages/harness/deerflow/agents/memory/providers/hindsight.py
index 592c5581..3319bb73 100644
--- a/offline-backend-20260512/backend/packages/harness/deerflow/agents/memory/providers/hindsight.py
+++ b/offline-backend-20260512/backend/packages/harness/deerflow/agents/memory/providers/hindsight.py
@@ -20,8 +20,8 @@ HTTP 客户端方式接入一个用户自起的 Hindsight Docker 实例 (``local
 document_id 与轮次计数
 ======================
 本 provider 被 ``build_memory_manager`` 每轮重新构造 —— 是无状态的。因此:
-- ``document_id`` 由 ``thread_id`` **确定性**派生,同一 thread 的所有轮次 retain
-  都落到同一个 Hindsight 文档,累积而非每轮碎片化成新文档。
+- ``document_id`` 每次 ``initialize`` 用带时间戳的新值,每轮对话的 retain 落到
+  各自独立的 Hindsight 文档。
 - ``retain_every_n_turns`` 的轮次判定依赖外部传入的 ``turn_index``
   (由 ``MemoryMiddleware`` 按对话历史算出);未传时退回进程内 ``_turn_counter``。
 
@@ -168,14 +168,14 @@ class HindsightProvider(MemoryProvider):
         return name.strip("-") or "deerflow"
 
     def _reset_retain_batch(self) -> None:
-        """重置 retain 批次状态。
+        """重置 retain 批次状态 (新的 document_id + 轮次清零)。
 
-        ``document_id`` 由 ``thread_id`` **确定性**派生 —— provider 虽然被每轮
-        重新构造,同一 thread 的所有轮次仍落到同一个 Hindsight 文档,累积成一份
-        而不是碎片化成一轮一个文档。无 thread 时 (例如 memory 工具镜像) 用统一
-        的兜底 id。轮次计数清零,仅作为 ``turn_index`` 缺失时的退路。
+        每次 ``initialize`` 用带时间戳的新 ``document_id`` —— 每轮对话的 retain
+        落到各自独立的 Hindsight 文档。轮次计数清零,仅作为 ``turn_index`` 缺失
+        时的退路。
         """
-        self._document_id = f"thread-{self._thread_id}" if self._thread_id else "thread-default"
+        ts = datetime.now().strftime("%Y%m%d_%H%M%S_%f")
+        self._document_id = f"{self._thread_id or 'thread'}-{ts}"
         self._turn_counter = 0
 
     def shutdown(self) -> None:
diff --git a/offline-backend-20260512/backend/tests/test_hindsight_provider.py b/offline-backend-20260512/backend/tests/test_hindsight_provider.py
index aa7d0449..da1cfe1b 100644
--- a/offline-backend-20260512/backend/tests/test_hindsight_provider.py
+++ b/offline-backend-20260512/backend/tests/test_hindsight_provider.py
@@ -108,16 +108,7 @@ class TestBankResolution:
 
 
 class TestDocumentId:
-    """document_id 必须由 thread_id 确定性派生 —— provider 每轮重建后仍稳定。"""
-
-    def test_deterministic_from_thread_id(self):
-        # 同一 thread,两个独立构造的 provider 必须算出同一个 document_id
-        p1 = HindsightProvider(HindsightMemoryConfig(api_url="http://x"))
-        p1.initialize(user_id="u", agent_id="a", thread_id="t-123", base_dir="")
-        p2 = HindsightProvider(HindsightMemoryConfig(api_url="http://x"))
-        p2.initialize(user_id="u", agent_id="a", thread_id="t-123", base_dir="")
-        assert p1._document_id == p2._document_id
-        assert "t-123" in p1._document_id
+    """document_id 每次 initialize 带时间戳 —— 每轮对话落到各自独立的文档。"""
 
     def test_different_threads_get_different_doc(self):
         p1 = HindsightProvider(HindsightMemoryConfig(api_url="http://x"))
@@ -126,28 +117,34 @@ class TestDocumentId:
         p2.initialize(user_id="u", agent_id="a", thread_id="t-2", base_dir="")
         assert p1._document_id != p2._document_id
 
+    def test_doc_id_carries_thread_prefix(self):
+        p = HindsightProvider(HindsightMemoryConfig(api_url="http://x"))
+        p.initialize(user_id="u", agent_id="a", thread_id="t-123", base_dir="")
+        # document_id 形如 "t-123-{时间戳}"
+        assert p._document_id.startswith("t-123-")
+
     def test_no_thread_id_uses_fallback(self):
         p = HindsightProvider(HindsightMemoryConfig(api_url="http://x"))
         p.initialize(user_id="u", agent_id="a", thread_id="", base_dir="")
-        assert p._document_id == "thread-default"
+        # 无 thread 时前缀塌缩成 "thread-"
+        assert p._document_id.startswith("thread-")
 
     def test_retain_writes_thread_document_id(self):
-        # sync_turn 落盘时带的 document_id 应是 thread 确定性 id,不含时间戳
+        # sync_turn 落盘时带的 document_id 形如 "t1-{时间戳}"
         client = _FakeClient()
         provider = _make_provider(client)  # thread_id="t1"
         provider.sync_turn("用户说啥", "助手答啥")
-        assert client.retained[0]["document_id"] == "thread-t1"
+        assert client.retained[0]["document_id"].startswith("t1-")
 
-    def test_recreated_providers_share_one_document(self):
-        # 模拟真实场景:同一 thread 连续 3 轮,每轮 provider 重建,
-        # 三轮 retain 必须落到同一个文档。
+    def test_recreated_providers_get_distinct_documents(self):
+        # 同一 thread 连续 3 轮、每轮 provider 重建 —— 各自落到独立文档
         doc_ids: set[str] = set()
         for turn in range(1, 4):
             client = _FakeClient()
             provider = _make_provider(client)  # 每轮重建,thread_id 固定 t1
             provider.sync_turn(f"u{turn}", f"a{turn}")
             doc_ids.add(client.retained[0]["document_id"])
-        assert doc_ids == {"thread-t1"}
+        assert len(doc_ids) == 3
 
 
 class TestPrefetchRecall:
@@ -334,7 +331,6 @@ class TestSessionSwitch:
         assert provider._thread_id == "t2"
         assert provider._turn_counter == 0
         assert provider._document_id != old_doc
-        assert provider._document_id == "thread-t2"
 
 
 class TestMisc: