diff --git a/src/service/utils/tools.ts b/src/service/utils/tools.ts
index 113ea54fd..8f43d3ce2 100644
--- a/src/service/utils/tools.ts
+++ b/src/service/utils/tools.ts
@@ -6,7 +6,7 @@ import { OpenApi, User } from '../mongo';
 import { formatPrice } from '@/utils/user';
 import { ERROR_ENUM } from '../errorCode';
 import { countChatTokens } from '@/utils/tools';
-import { ChatCompletionRequestMessageRoleEnum } from 'openai';
+import { ChatCompletionRequestMessageRoleEnum, ChatCompletionRequestMessage } from 'openai';
 import { ChatModelEnum } from '@/constants/model';
 
 /* 密码加密 */
@@ -88,6 +88,13 @@ export const authOpenApiKey = async (req: NextApiRequest) => {
 export const httpsAgent = (fast: boolean) =>
   fast ? global.httpsAgentFast : global.httpsAgentNormal;
 
+/* delete invalid symbol */
+const simplifyStr = (str: string) =>
+  str
+    .replace(/\n+/g, '\n') // 连续空行
+    .replace(/[^\S\r\n]+/g, ' ') // 连续空白内容
+    .trim();
+
 /* 聊天内容 tokens 截断 */
 export const openaiChatFilter = ({
   model,
@@ -98,40 +105,44 @@ export const openaiChatFilter = ({
   prompts: ChatItemType[];
   maxTokens: number;
 }) => {
-  const formatPrompts = prompts.map((item) => ({
-    obj: item.obj,
-    value: item.value
-      // .replace(/[\u3000\u3001\uff01-\uff5e\u3002]/g, ' ') // 中文标点改空格
-      .replace(/\n+/g, '\n') // 连续空行
-      .replace(/[^\S\r\n]+/g, ' ') // 连续空白内容
-      .trim()
-  }));
-
-  let chats: ChatItemType[] = [];
-  let systemPrompt: ChatItemType | null = null;
-
-  //  System 词保留
-  if (formatPrompts[0]?.obj === 'SYSTEM') {
-    systemPrompt = formatPrompts.shift() as ChatItemType;
-  }
-
-  // 格式化文本内容成 chatgpt 格式
+  // role map
   const map = {
     Human: ChatCompletionRequestMessageRoleEnum.User,
     AI: ChatCompletionRequestMessageRoleEnum.Assistant,
     SYSTEM: ChatCompletionRequestMessageRoleEnum.System
   };
 
+  let rawTextLen = 0;
+  const formatPrompts = prompts.map((item) => {
+    const val = simplifyStr(item.value);
+    rawTextLen += val.length;
+    return {
+      role: map[item.obj],
+      content: val
+    };
+  });
+
+  // 长度太小时，不需要进行 token 截断
+  if (rawTextLen < maxTokens * 0.5) {
+    return formatPrompts;
+  }
+
+  // 根据 tokens 截断内容
+  const chats: ChatCompletionRequestMessage[] = [];
+  let systemPrompt: ChatCompletionRequestMessage | null = null;
+
+  //  System 词保留
+  if (formatPrompts[0]?.role === 'system') {
+    systemPrompt = formatPrompts.shift() as ChatCompletionRequestMessage;
+  }
+
   let messages: { role: ChatCompletionRequestMessageRoleEnum; content: string }[] = [];
 
   // 从后往前截取对话内容
   for (let i = formatPrompts.length - 1; i >= 0; i--) {
     chats.unshift(formatPrompts[i]);
 
-    messages = (systemPrompt ? [systemPrompt, ...chats] : chats).map((item) => ({
-      role: map[item.obj],
-      content: item.value
-    }));
+    messages = systemPrompt ? [systemPrompt, ...chats] : chats;
 
     const tokens = countChatTokens({
       model,
@@ -147,7 +158,7 @@ export const openaiChatFilter = ({
   return messages;
 };
 
-/* system 内容截断 */
+/* system 内容截断. 相似度从高到低 */
 export const systemPromptFilter = ({
   model,
   prompts,
@@ -161,7 +172,7 @@ export const systemPromptFilter = ({
 
   // 从前往前截取
   for (let i = 0; i < prompts.length; i++) {
-    const prompt = prompts[i].replace(/\n+/g, '\n');
+    const prompt = simplifyStr(prompts[i]);
 
     splitText += `${prompt}\n`;
     const tokens = countChatTokens({ model, messages: [{ role: 'system', content: splitText }] });
@@ -170,5 +181,5 @@ export const systemPromptFilter = ({
     }
   }
 
-  return splitText.slice(0, splitText.length - 1).replace(/\n+/g, '\n');
+  return splitText.slice(0, splitText.length - 1);
 };