diff --git a/plugins/ai_auto_response/context_builder.py b/plugins/ai_auto_response/context_builder.py
index 7b4ebe8..8248ced 100644
--- a/plugins/ai_auto_response/context_builder.py
+++ b/plugins/ai_auto_response/context_builder.py
@@ -4,6 +4,9 @@ from typing import Dict, List
 
 
 class ContextBuilder:
+    def __init__(self, recent_context_size: int = 30):
+        self.recent_context_size = max(int(recent_context_size or 30), 1)
+
     def build(
         self,
         *,
@@ -20,7 +23,7 @@ class ContextBuilder:
         vector_memories: List[Dict],
     ) -> Dict:
         recent_lines = []
-        for item in recent_messages[-8:]:
+        for item in recent_messages[-self.recent_context_size:]:
             msg_sender = item.get("sender_name") or item.get("sender") or "未知成员"
             msg_content = item.get("content") or item.get("message") or ""
             if msg_content:
diff --git a/plugins/ai_auto_response/main.py b/plugins/ai_auto_response/main.py
index 918b4e5..65be9a1 100644
--- a/plugins/ai_auto_response/main.py
+++ b/plugins/ai_auto_response/main.py
@@ -87,7 +87,7 @@ class AIAutoResponsePlugin(MessagePluginInterface):
         merged_memory_config.update(self._config.get("memory", {}) or {})
         self.memory_store = MemoryStore(self.db_manager, merged_memory_config)
         self.vector_memory = VectorMemoryStore(self._config.get("memory", {}) or {})
-        self.context_builder = ContextBuilder()
+        self.context_builder = ContextBuilder(int((self._config.get("mode", {}) or {}).get("recent_context_size", 30)))
         self.response_planner = ResponsePlanner()
         self.llm_client = LLMClient(self._config.get("api", {}) or {})
         self.filters = self._config.get("filters", {}) or {}
@@ -344,7 +344,7 @@ class AIAutoResponsePlugin(MessagePluginInterface):
         return (current_ts - last_room_reply) >= room_cd
 
     def _build_user_prompt(self, context: Dict, memory_hints: Dict) -> str:
-        recent_text = "\n".join(context.get("recent_messages", [])[-8:]) or "暂无"
+        recent_text = "\n".join(context.get("recent_messages", [])) or "暂无"
         reply_mode = context.get("reply_mode", "social_short")
         length_rule = self._build_length_rule(reply_mode)
         return (