diff --git a/src/components/chat/ChatMain.vue b/src/components/chat/ChatMain.vue
index 85f0eb0..eaa8baf 100644
--- a/src/components/chat/ChatMain.vue
+++ b/src/components/chat/ChatMain.vue
@@ -223,15 +223,25 @@ async function handleSend(
     await chatStore.createConversation();
   }
 
-  // 从当前会话中提取历史消息（用于上下文记忆），在添加新消息之前提取
+  // 获取系统提示词（优先使用传入的，否则使用会话设置）
+  const systemPrompt = options?.systemPrompt || currentConversation.value?.settings?.systemPrompt;
+
+  // 检查是否需要添加系统消息
   const existingMessages = currentConversation.value?.messages || [];
+  const hasSystemMessage = existingMessages.some((m: any) => m.role === MessageRole.SYSTEM);
+
+  // 如果有系统提示词且对话中没有系统消息，添加系统消息
+  if (systemPrompt && !hasSystemMessage) {
+    await chatStore.addMessage(MessageRole.SYSTEM, {
+      type: MessageType.TEXT,
+      text: systemPrompt,
+    });
+  }
+
+  // 从当前会话中提取历史消息（用于上下文记忆），在添加新消息之前提取
+  const updatedMessages = currentConversation.value?.messages || [];
   const MAX_HISTORY_ROUNDS = 20; // 最多保留最近 20 轮（40 条消息）
-  const historyMessages = existingMessages
-    .filter(
-      (m: any) =>
-        m.role === MessageRole.USER || m.role === MessageRole.ASSISTANT,
-    )
-    .filter((m: any) => m.content?.text) // 过滤掉空消息
+  const historyMessages = updatedMessages.filter((m: any) => m.content?.text) // 过滤掉空消息
     .slice(-(MAX_HISTORY_ROUNDS * 2))
     .map((m: any) => ({ role: m.role, content: m.content.text }));
 
diff --git a/src/components/chat/MessageList.vue b/src/components/chat/MessageList.vue
index d8fa2c9..bf6bd71 100644
--- a/src/components/chat/MessageList.vue
+++ b/src/components/chat/MessageList.vue
@@ -3,7 +3,7 @@
     <div ref="containerRef" class="message-list" @scroll="handleScroll">
       <!-- 欢迎界面 -->
       <WelcomeScreen
-        v-if="messages.length === 0"
+        v-if="visibleMessages.length === 0"
         @select="$emit('select-suggestion', $event)"
       />
 
@@ -12,12 +12,12 @@
         <div class="messages-wrapper">
           <TransitionGroup name="message">
             <MessageBubble
-              v-for="(message, index) in messages"
+              v-for="(message, index) in visibleMessages"
               :key="message.id"
               :message="message"
               :show-timestamp="showTimestamp"
               :compact="compact"
-              :is-New="index === messages.length - 1"
+              :is-New="index === visibleMessages.length - 1"
               @retry="$emit('retry', message.id)"
               @regenerate="$emit('regenerate', message.id)"
               @copy="handleCopy(message)"
@@ -62,12 +62,13 @@
 </template>
 
 <script setup lang="ts">
-import { ref, watch, nextTick, onMounted } from "vue";
+import { ref, watch, nextTick, onMounted, computed } from "vue";
 import { useChatStore } from "@/stores/chat";
 import MessageBubble from "@/components/message/MessageBubble.vue";
 import WelcomeScreen from "./WelcomeScreen.vue";
 import { Bot, ChevronDown } from "@/components/icons";
 import type { Message, Attachment, VideoInfo, Suggestion } from "@/types/chat";
+import { MessageRole } from "@/types/chat";
 
 const props = withDefaults(
   defineProps<{
@@ -83,6 +84,13 @@ const props = withDefaults(
   },
 );
 
+// 过滤掉系统消息，不显示在前端
+const visibleMessages = computed(() => {
+  return props.messages.filter(
+    (message) => message.role !== MessageRole.SYSTEM
+  );
+});
+
 const emit = defineEmits<{
   retry: [messageId: string];
   regenerate: [messageId: string];
@@ -175,7 +183,7 @@ function handleDownloadFile(file: Attachment) {
 
 // 监听消息变化
 watch(
-  () => props.messages.length,
+  () => visibleMessages.value.length,
   (newLen, oldLen) => {
     if (newLen > oldLen) {
       if (isAutoScrolling.value) {
@@ -191,7 +199,7 @@ watch(
 
 // 监听最后一条消息的内容变化
 watch(
-  () => props.messages[props.messages.length - 1]?.content.text,
+  () => visibleMessages.value[visibleMessages.value.length - 1]?.content.text,
   () => {
     if (isAutoScrolling.value) {
       nextTick(() => {
diff --git a/src/components/message/components/ThinkingNode.vue b/src/components/message/components/ThinkingNode.vue
index 6981378..33ad9cf 100644
--- a/src/components/message/components/ThinkingNode.vue
+++ b/src/components/message/components/ThinkingNode.vue
@@ -163,7 +163,7 @@ async function textCopy(data: any) {
 /* 可折叠内容 */
 .thinking-content {
   max-height: 2000px;
-  overflow: hidden;
+  overflow: auto;
   transition:
     max-height 0.35s ease,
     opacity 0.25s ease;
diff --git a/src/components/modals/ConversationSettingsModal.vue b/src/components/modals/ConversationSettingsModal.vue
index 4b17db0..4f263b7 100644
--- a/src/components/modals/ConversationSettingsModal.vue
+++ b/src/components/modals/ConversationSettingsModal.vue
@@ -202,6 +202,7 @@ import FormSelect from "@/components/ui/FormSelect.vue";
 import { MessageSquare, X, Check, Trash2 } from "@/components/icons";
 import { chatApi } from "@/services/api.ts";
 import type { ConversationSettings } from "@/types/chat";
+import { MessageRole, MessageType } from "@/types/chat";
 
 const chatStore = useChatStore();
 const settingsStore = useSettingsStore();
@@ -359,6 +360,25 @@ function handleSave() {
   // 调用更新对话设置的方法
   chatStore.updateConversationSettings(conversation.value.id, convSettings);
 
+  // 如果系统提示词有变化，更新消息列表中的系统消息
+  if (localSettings.value.systemPrompt) {
+    const messages = conversation.value.messages || [];
+    const systemMsgIndex = messages.findIndex((m: any) => m.role === MessageRole.SYSTEM);
+
+    if (systemMsgIndex >= 0) {
+      // 更新已有的系统消息
+      chatStore.updateMessage(messages[systemMsgIndex].id, {
+        content: {
+          type: MessageType.TEXT,
+          text: localSettings.value.systemPrompt,
+        },
+      });
+    } else {
+      // 添加新的系统消息（放在消息列表开头）
+      chatStore.addSystemMessage(conversation.value.id, localSettings.value.systemPrompt);
+    }
+  }
+
   close();
 
   // 显示成功提示
diff --git a/src/services/api.ts b/src/services/api.ts
index 982b8da..a581795 100644
--- a/src/services/api.ts
+++ b/src/services/api.ts
@@ -121,21 +121,36 @@ class ChatApi {
     }
 
     // 将前端简化的请求翻译为 OpenAI 兼容的规范请求体
-    // 构建 messages 数组：system + 历史消息 + 当前用户消息
-    const systemMessage = {
-      role: "system",
-      content:
-        request.systemPrompt ||
-        "你是一个智能助手，可以分析用户发送的文字，文件或图片内容，并进行回答。",
-    };
-    const currentUserMessage = {
-      role: "user",
-      content: userContent,
-    };
-    const allMessages =
-      request.history && request.history.length > 0
-        ? [systemMessage, ...request.history, currentUserMessage]
-        : [systemMessage, currentUserMessage];
+    // 检查历史消息中是否已有系统消息
+    const historyHasSystem = request.history?.some((m) => m.role === "system");
+
+    // 构建 messages 数组
+    let allMessages: Array<{ role: string; content: any }>;
+
+    if (request.history && request.history.length > 0) {
+      // 如果历史中有系统消息，直接使用历史消息
+      if (historyHasSystem) {
+        allMessages = [...request.history, { role: "user", content: userContent }];
+      } else {
+        // 否则添加系统消息
+        const systemMessage = {
+          role: "system",
+          content:
+            request.systemPrompt ||
+            "你是一个智能助手，可以分析用户发送的文字，文件或图片内容，并进行回答。",
+        };
+        allMessages = [systemMessage, ...request.history, { role: "user", content: userContent }];
+      }
+    } else {
+      // 没有历史消息，添加系统消息
+      const systemMessage = {
+        role: "system",
+        content:
+          request.systemPrompt ||
+          "你是一个智能助手，可以分析用户发送的文字，文件或图片内容，并进行回答。",
+      };
+      allMessages = [systemMessage, { role: "user", content: userContent }];
+    }
 
     const openAiRequest = {
       model: request.model || "glm-4-flash",
diff --git a/src/stores/chat.ts b/src/stores/chat.ts
index c189be1..06efcf5 100644
--- a/src/stores/chat.ts
+++ b/src/stores/chat.ts
@@ -290,6 +290,38 @@ export const useChatStore = defineStore("chat", () => {
     return message;
   }
 
+  // 添加系统消息（放在消息列表开头）
+  async function addSystemMessage(
+    conversationId: string,
+    systemPrompt: string
+  ): Promise<Message> {
+    const conversation = conversations.value.find((c) => c.id === conversationId);
+    if (!conversation) {
+      throw new Error("Conversation not found");
+    }
+
+    const message: Message = {
+      id: generateId(),
+      role: MessageRole.SYSTEM,
+      content: { type: "text" as const, text: systemPrompt },
+      timestamp: Date.now(),
+      isStreaming: false,
+    } as Message;
+
+    // 将系统消息插入到消息列表开头
+    conversation.messages.unshift(message);
+    conversation.updatedAt = Date.now();
+
+    // 异步保存
+    try {
+      await conversationApi.addMessage(conversationId, message);
+    } catch (error) {
+      console.error("Failed to save system message:", error);
+    }
+
+    return message;
+  }
+
   // 更新消息
   async function updateMessage(messageId: string, updates: Partial<Message>) {
     const conversation = currentConversation.value;
@@ -479,6 +511,7 @@ export const useChatStore = defineStore("chat", () => {
     renameConversation,
     updateConversationSettings,
     addMessage,
+    addSystemMessage,
     updateMessage,
     updateMessageContent,
     saveConversation,