diff --git a/src/chat/message_receive/chat_stream.py b/src/chat/message_receive/chat_stream.py
index e16930ffe..48a7c2740 100644
--- a/src/chat/message_receive/chat_stream.py
+++ b/src/chat/message_receive/chat_stream.py
@@ -20,6 +20,9 @@ install(extra_lines=3)
 
 logger = get_logger("chat_stream")
 
+# 用于存储后台任务的集合，防止被垃圾回收
+_background_tasks: set[asyncio.Task] = set()
+
 
 class ChatStream:
     """聊天流对象，存储一个完整的聊天上下文"""
@@ -406,6 +409,40 @@ class ChatManager:
         key = "_".join(components)
         return hashlib.sha256(key.encode()).hexdigest()
 
+    async def _process_message(self, message: DatabaseMessages):
+        """
+        [新] 在消息处理流程中加入用户信息同步。
+        """
+        # 1. 从消息中提取用户信息
+        user_info = getattr(message, "user_info", None)
+        if not user_info:
+            return
+
+        platform = getattr(user_info, "platform", None)
+        user_id = getattr(user_info, "user_id", None)
+        nickname = getattr(user_info, "user_nickname", None)
+        cardname = getattr(user_info, "user_cardname", None)
+
+        if not platform or not user_id:
+            return
+
+        # 2. 异步执行用户信息同步
+        try:
+            from src.person_info.person_info import get_person_info_manager
+            person_info_manager = get_person_info_manager()
+            
+            # 创建一个后台任务来执行同步，不阻塞当前流程
+            sync_task = asyncio.create_task(
+                person_info_manager.sync_user_info(platform, user_id, nickname, cardname)
+            )
+            # 将任务添加到集合中以防止被垃圾回收
+            # 可以在适当的地方（如程序关闭时）清理这个集合
+            _background_tasks.add(sync_task)
+            sync_task.add_done_callback(_background_tasks.discard)
+
+        except Exception as e:
+            logger.error(f"创建用户信息同步任务失败: {e}")
+
     async def get_or_create_stream(
         self, platform: str, user_info: UserInfo, group_info: GroupInfo | None = None
     ) -> ChatStream:
@@ -437,7 +474,10 @@ class ChatManager:
                 # 检查是否有最后一条消息（现在使用 DatabaseMessages）
                 from src.common.data_models.database_data_model import DatabaseMessages
                 if stream_id in self.last_messages and isinstance(self.last_messages[stream_id], DatabaseMessages):
-                    await stream.set_context(self.last_messages[stream_id])
+                    last_message = self.last_messages[stream_id]
+                    await stream.set_context(last_message)
+                    # 在这里调用消息处理
+                    await self._process_message(last_message)
                 else:
                     logger.debug(f"聊天流 {stream_id} 不在最后消息列表中，可能是新创建的或还没有消息")
                 return stream
@@ -634,23 +674,23 @@ class ChatManager:
         except Exception as e:
             logger.debug(f"批量写入器保存聊天流失败，使用原始方法: {e}")
 
-        # 尝试使用数据库批量调度器（回退方案1）
-        try:
-            from src.common.database.db_batch_scheduler import batch_update, get_batch_session
-
-            async with get_batch_session():
-                # 使用批量更新
-                result = await batch_update(
-                    model_class=ChatStreams,
-                    conditions={"stream_id": stream_data_dict["stream_id"]},
-                    data=ChatManager._prepare_stream_data(stream_data_dict),
-                )
-                if result and result > 0:
-                    stream.saved = True
-                    logger.debug(f"聊天流 {stream.stream_id} 通过批量调度器保存成功")
-                    return
-        except (ImportError, Exception) as e:
-            logger.debug(f"批量调度器保存聊天流失败，使用原始方法: {e}")
+        # 尝试使用数据库批量调度器（回退方案1） - [已废弃]
+        # try:
+        #     from src.common.database.optimization.batch_scheduler import batch_update, get_batch_session
+        #
+        #     async with get_batch_session():
+        #         # 使用批量更新
+        #         result = await batch_update(
+        #             model_class=ChatStreams,
+        #             conditions={"stream_id": stream_data_dict["stream_id"]},
+        #             data=ChatManager._prepare_stream_data(stream_data_dict),
+        #         )
+        #         if result and result > 0:
+        #             stream.saved = True
+        #             logger.debug(f"聊天流 {stream.stream_id} 通过批量调度器保存成功")
+        #             return
+        # except (ImportError, Exception) as e:
+        #     logger.debug(f"批量调度器保存聊天流失败，使用原始方法: {e}")
 
         # 回退到原始方法（最终方案）
         async def _db_save_stream_async(s_data_dict: dict):
diff --git a/src/chat/replyer/default_generator.py b/src/chat/replyer/default_generator.py
index a760e6025..ee4819524 100644
--- a/src/chat/replyer/default_generator.py
+++ b/src/chat/replyer/default_generator.py
@@ -1332,8 +1332,8 @@ class DefaultReplyer:
             ),
             "cross_context": asyncio.create_task(
                 self._time_and_run_task(
-                    Prompt.build_cross_context(chat_id, "s4u", target_user_info),
-                    "cross_context",
+                    # cross_context 的构建已移至 prompt.py
+                    asyncio.sleep(0, result=""), "cross_context"
                 )
             ),
             "notice_block": asyncio.create_task(
@@ -1521,6 +1521,8 @@ class DefaultReplyer:
 
         # 使用新的统一Prompt系统 - 创建PromptParameters
         prompt_parameters = PromptParameters(
+            platform=platform,
+            user_id=user_id,
             chat_scene=chat_scene_prompt,
             chat_id=chat_id,
             is_group_chat=is_group_chat,
diff --git a/src/chat/utils/prompt.py b/src/chat/utils/prompt.py
index 668884d93..6701665d8 100644
--- a/src/chat/utils/prompt.py
+++ b/src/chat/utils/prompt.py
@@ -709,9 +709,17 @@ class Prompt:
     async def _build_relation_info(self) -> dict[str, Any]:
         """构建与对话目标相关的关系信息."""
         try:
-            # 调用静态方法来执行实际的构建逻辑
-            relation_info = await Prompt.build_relation_info(
-                self.parameters.chat_id, self.parameters.reply_to
+            # [重构] 直接从 PromptParameters 获取稳定的用户身份信息
+            platform = self.parameters.platform
+            user_id = self.parameters.user_id
+
+            if not platform or not user_id:
+                logger.warning("无法从参数中获取platform或user_id，跳过关系信息构建")
+                return {"relation_info_block": ""}
+
+            # 调用新的、基于ID的静态方法
+            relation_info = await Prompt.build_relation_info_by_user_id(
+                self.parameters.chat_id, platform, user_id
             )
             return {"relation_info_block": relation_info}
         except Exception as e:
@@ -1063,43 +1071,29 @@ class Prompt:
         return sender, target
 
     @staticmethod
-    async def build_relation_info(chat_id: str, reply_to: str) -> str:
-        """构建关于回复目标用户的关系信息字符串.
-
-        Args:
-            chat_id: 当前聊天的ID。
-            reply_to: 被回复的原始消息字符串。
-
-        Returns:
-            str: 格式化后的关系信息字符串，或在失败时返回空字符串。
+    async def build_relation_info_by_user_id(chat_id: str, platform: str, user_id: str) -> str:
+        """
+        [新] 根据用户ID构建关系信息字符串。
         """
         from src.person_info.relationship_fetcher import relationship_fetcher_manager
+        
+        person_info_manager = get_person_info_manager()
+        person_id = person_info_manager.get_person_id(platform, user_id)
+
+        if not person_id:
+            logger.warning(f"构建关系信息时未找到用户 platform={platform}, user_id={user_id}")
+            return f"你似乎还不认识这位用户（ID: {user_id}），这是你们的第一次互动。"
 
         relationship_fetcher = relationship_fetcher_manager.get_fetcher(chat_id)
-
-        if not reply_to:
-            return ""
-        # 解析出回复目标的发送者
-        sender, text = Prompt.parse_reply_target(reply_to)
-        if not sender or not text:
-            return ""
-
-        # 根据发送者名称查找其用户ID
-        person_info_manager = get_person_info_manager()
-        person_id = await person_info_manager.get_person_id_by_person_name(sender)
-        if not person_id:
-            logger.warning(f"未找到用户 {sender} 的ID，跳过信息提取")
-            return f"你完全不认识{sender}，不理解ta的相关信息。"
-
-        # 使用关系提取器构建用户关系信息和聊天流印象
-        user_relation_info = await relationship_fetcher.build_relation_info(
-            person_id, points_num=5
-        )
-        stream_impression = await relationship_fetcher.build_chat_stream_impression(
-            chat_id
+        
+        # 并行构建用户信息和聊天流印象
+        user_relation_info_task = relationship_fetcher.build_relation_info(person_id, points_num=5)
+        stream_impression_task = relationship_fetcher.build_chat_stream_impression(chat_id)
+        
+        user_relation_info, stream_impression = await asyncio.gather(
+            user_relation_info_task, stream_impression_task
         )
 
-        # 组合两部分信息
         info_parts = []
         if user_relation_info:
             info_parts.append(user_relation_info)
@@ -1149,6 +1143,7 @@ class Prompt:
         Returns:
             str: 构建好的跨群聊上下文字符串。
         """
+        logger.info(f"Building cross context with target_user_info: {target_user_info}")
         if not global_config.cross_context.enable:
             return ""
 
@@ -1167,32 +1162,22 @@ class Prompt:
 
         return ""
 
-    @staticmethod
-    async def parse_reply_target_id(reply_to: str) -> str:
-        """从回复目标字符串中解析出原始发送者的用户ID.
-
-        Args:
-            reply_to: 回复目标字符串。
-
-        Returns:
-            str: 找到的用户ID，如果找不到则返回空字符串。
-        """
-        if not reply_to:
-            return ""
-
-        # 首先，解析出发送者的名称
-        sender, _ = Prompt.parse_reply_target(reply_to)
-        if not sender:
-            return ""
-
-        # 然后，通过名称查询用户ID
-        person_info_manager = get_person_info_manager()
-        person_id = await person_info_manager.get_person_id_by_person_name(sender)
-        if person_id:
-            user_id = await person_info_manager.get_value(person_id, "user_id")
-            return str(user_id) if user_id else ""
-
-        return ""
+    # [废弃] 该函数完全依赖于不稳定的名称解析，应被移除
+    # @staticmethod
+    # async def parse_reply_target_id(reply_to: str) -> str:
+    #     """从回复目标字符串中解析出原始发送者的用户ID."""
+    #     if not reply_to:
+    #         return ""
+    #     sender, _ = Prompt.parse_reply_target(reply_to)
+    #     if not sender:
+    #         return ""
+    #     person_info_manager = get_person_info_manager()
+    #     # [脆弱点] 使用了不稳健的按名称查询
+    #     person_id = await person_info_manager.get_person_id_by_name_robust(sender)
+    #     if person_id:
+    #         user_id = await person_info_manager.get_value(person_id, "user_id")
+    #         return str(user_id) if user_id else ""
+    #     return ""
 
 
 # 工厂函数
diff --git a/src/chat/utils/prompt_params.py b/src/chat/utils/prompt_params.py
index 707b18575..5ca376a2a 100644
--- a/src/chat/utils/prompt_params.py
+++ b/src/chat/utils/prompt_params.py
@@ -11,6 +11,8 @@ class PromptParameters:
 
     # 基础参数
     chat_id: str = ""
+    platform: str = ""
+    user_id: str = ""
     is_group_chat: bool = False
     sender: str = ""
     target: str = ""
diff --git a/src/person_info/person_info.py b/src/person_info/person_info.py
index 6165d1a2a..4cd1b3eb7 100644
--- a/src/person_info/person_info.py
+++ b/src/person_info/person_info.py
@@ -135,6 +135,113 @@ class PersonInfoManager:
             logger.error(f"根据用户名 {person_name} 获取用户ID时出错: {e}")
             return ""
 
+    @staticmethod
+    @cached(ttl=600, key_prefix="person_info_by_user_id", use_kwargs=False)
+    async def get_person_info_by_user_id(platform: str, user_id: str) -> dict | None:
+        """[新] 根据 platform 和 user_id 获取用户信息字典"""
+        if not platform or not user_id:
+            return None
+        
+        person_id = PersonInfoManager.get_person_id(platform, user_id)
+        crud = CRUDBase(PersonInfo)
+        record = await crud.get_by(person_id=person_id)
+        
+        if not record:
+            return None
+            
+        # 将 SQLAlchemy 模型对象转换为字典
+        return {c.name: getattr(record, c.name) for c in record.__table__.columns}
+
+    @staticmethod
+    @cached(ttl=600, key_prefix="person_info_by_person_id", use_kwargs=False)
+    async def get_person_info_by_person_id(person_id: str) -> dict | None:
+        """[新] 根据 person_id 获取用户信息字典"""
+        if not person_id:
+            return None
+        
+        crud = CRUDBase(PersonInfo)
+        record = await crud.get_by(person_id=person_id)
+        
+        if not record:
+            return None
+            
+        # 将 SQLAlchemy 模型对象转换为字典
+        return {c.name: getattr(record, c.name) for c in record.__table__.columns}
+
+    @staticmethod
+    async def get_person_id_by_name_robust(name: str) -> str | None:
+        """[新] 稳健地根据名称获取 person_id，按 person_name -> nickname 顺序回退"""
+        if not name:
+            return None
+
+        crud = CRUDBase(PersonInfo)
+        
+        # 1. 按 person_name 查询
+        records = await crud.get_multi(person_name=name, limit=1)
+        if records:
+            return records[0].person_id
+            
+        # 2. 按 nickname 查询
+        records = await crud.get_multi(nickname=name, limit=1)
+        if records:
+            return records[0].person_id
+
+        return None
+
+    @staticmethod
+    @staticmethod
+    @cached(ttl=600, key_prefix="person_info_by_name_robust", use_kwargs=False)
+    async def get_person_info_by_name_robust(name: str) -> dict | None:
+        """[新] 稳健地根据名称获取用户信息，按 person_name -> nickname 顺序回退"""
+        person_id = await PersonInfoManager.get_person_id_by_name_robust(name)
+        if person_id:
+            return await PersonInfoManager.get_person_info_by_person_id(person_id)
+        return None
+
+    @staticmethod
+    async def sync_user_info(platform: str, user_id: str, nickname: str | None, cardname: str | None) -> str:
+        """
+        [新] 同步用户信息。查询或创建用户，并更新易变信息（如昵称）。
+        返回 person_id。
+        """
+        if not platform or not user_id:
+            raise ValueError("platform 和 user_id 不能为空")
+
+        person_id = PersonInfoManager.get_person_id(platform, user_id)
+        crud = CRUDBase(PersonInfo)
+        record = await crud.get_by(person_id=person_id)
+
+        effective_name = cardname or nickname or "未知用户"
+
+        if record:
+            # 用户已存在，检查是否需要更新
+            updates = {}
+            if nickname and record.nickname != nickname:
+                updates["nickname"] = nickname
+            
+            if updates:
+                await crud.update(record.id, updates)
+                logger.debug(f"用户 {person_id} 信息已更新: {updates}")
+        else:
+            # 用户不存在，创建新用户
+            logger.info(f"新用户 {platform}:{user_id}，将创建记录。")
+            unique_person_name = await PersonInfoManager._generate_unique_person_name(effective_name)
+            
+            new_person_data = {
+                "person_id": person_id,
+                "platform": platform,
+                "user_id": str(user_id),
+                "nickname": nickname,
+                "person_name": unique_person_name,
+                "name_reason": "首次遇见时自动设置",
+                "know_since": int(time.time()),
+                "last_know": int(time.time()),
+            }
+            await PersonInfoManager._safe_create_person_info(person_id, new_person_data)
+
+        return person_id
+
+    @staticmethod
     @staticmethod
     async def first_knowing_some_one(platform: str, user_id: str, user_nickname: str, user_cardname: str):
         """判断是否认识某人"""