diff --git a/astrbot/core/pipeline/process_stage/method/llm_request.py b/astrbot/core/pipeline/process_stage/method/llm_request.py
index c6a87b37c..35e9f5f50 100644
--- a/astrbot/core/pipeline/process_stage/method/llm_request.py
+++ b/astrbot/core/pipeline/process_stage/method/llm_request.py
@@ -38,6 +38,9 @@ class LLMRequestSubStage(Stage):
         self.max_context_length = ctx.astrbot_config["provider_settings"][
             "max_context_length"
         ]  # int
+        self.dequeue_context_length = ctx.astrbot_config["provider_settings"][
+            "dequeue_context_length"
+        ]  # int
         self.streaming_response = ctx.astrbot_config["provider_settings"][
             "streaming_response"
         ]  # bool
@@ -135,7 +138,7 @@ class LLMRequestSubStage(Stage):
             and len(req.contexts) // 2 > self.max_context_length
         ):
             logger.debug("上下文长度超过限制，将截断。")
-            req.contexts = req.contexts[-self.max_context_length * 2 :]
+            req.contexts = req.contexts[-(self.max_context_length - self.dequeue_context_length) * 2 :]
 
         # session_id
         if not req.session_id: