diff --git a/src/api.ts b/src/api.ts
index 349c71c..23dfb34 100644
--- a/src/api.ts
+++ b/src/api.ts
@@ -160,12 +160,14 @@ export const Submission = {
       js?: string
       prompt?: string
     },
+    messageId?: number,
   ) {
     const { prompt, ...rest } = code
     const data = {
       task_id: taskId,
       ...rest,
       prompt: prompt || null,
+      message_id: messageId ?? null,
     }
     const res = await http.post("/submission/", data)
     return res.data
@@ -260,6 +262,13 @@ export const Prompt = {
     if (!convs.length) return []
     return this.getMessages(convs[0].id)
   },
+
+  async deleteMessagePair(
+    messageId: number,
+  ): Promise<{ deleted: boolean; submission_deleted: boolean }> {
+    const res = await http.delete(`/prompt/messages/${messageId}/pair`)
+    return res.data
+  },
 }
 
 export const Helper = {
diff --git a/src/components/ai/PromptPanel.vue b/src/components/ai/PromptPanel.vue
index 0a2fa9d..e55fe5d 100644
--- a/src/components/ai/PromptPanel.vue
+++ b/src/components/ai/PromptPanel.vue
@@ -1,10 +1,36 @@
 <template>
   <div class="prompt-panel">
     <div class="messages" ref="messagesRef">
-      <div v-for="(msg, i) in messages" :key="i" :class="['message', msg.role]">
-        <div class="message-role">{{ msg.role === "user" ? "我" : "AI" }}</div>
-        <div class="message-content" v-html="renderContent(msg)"></div>
+      <div
+        v-for="(pair, pi) in pairs"
+        :key="pair.assistantMsg?.id ?? 'user-' + pair.index"
+        class="message-pair"
+        :class="{ 'has-delete': pair.assistantMsg?.id && !streaming }"
+      >
+        <!-- Delete button: only shown on hover when pair has assistant id and not streaming -->
+        <button
+          v-if="pair.assistantMsg?.id && !streaming"
+          class="pair-delete-btn"
+          @click="deletePair(pair.assistantMsg!.id!)"
+          title="删除这轮对话及关联提交"
+        >
+          <Icon icon="lucide:trash-2" :width="14" />
+        </button>
+
+        <!-- User message -->
+        <div class="message user">
+          <div class="message-role">我</div>
+          <div class="message-content" v-html="renderContent(pair.userMsg)"></div>
+        </div>
+
+        <!-- Assistant message -->
+        <div v-if="pair.assistantMsg" class="message assistant">
+          <div class="message-role">AI</div>
+          <div class="message-content" v-html="renderContent(pair.assistantMsg)"></div>
+        </div>
       </div>
+
+      <!-- Streaming indicator -->
       <div v-if="streaming" class="message assistant">
         <div class="message-role">AI</div>
         <div v-if="!streamingContent" class="typing-indicator">
@@ -51,9 +77,11 @@
 </template>
 
 <script setup lang="ts">
-import { ref, watch, nextTick } from "vue"
+import { ref, watch, nextTick, computed } from "vue"
 import { useStorage } from "@vueuse/core"
 import { marked, Renderer } from "marked"
+import { useMessage } from "naive-ui"
+import { Icon } from "@iconify/vue"
 import {
   messages,
   streaming,
@@ -62,9 +90,11 @@ import {
   sendPrompt,
   stopPrompt,
 } from "../../store/prompt"
+import { Prompt } from "../../api"
 
 const input = ref("")
 const messagesRef = ref<HTMLElement>()
+const naiveMessage = useMessage()
 
 const modelOptions = [
   { label: "豆包", value: "doubao-seed-2-0-lite-260215" },
@@ -72,6 +102,40 @@ const modelOptions = [
 ]
 const selectedModel = useStorage("prompt-model", "deepseek-chat")
 
+// Group messages into user+assistant pairs
+const pairs = computed(() => {
+  const result: Array<{
+    userMsg: { role: string; content: string; id?: number }
+    assistantMsg: { role: string; content: string; id?: number; code?: any } | null
+    index: number
+  }> = []
+  const msgs = messages.value
+  let i = 0
+  while (i < msgs.length) {
+    if (msgs[i].role === "user") {
+      const assistantMsg = msgs[i + 1]?.role === "assistant" ? msgs[i + 1] : null
+      result.push({ userMsg: msgs[i], assistantMsg, index: i })
+      i += assistantMsg ? 2 : 1
+    } else {
+      i++
+    }
+  }
+  return result
+})
+
+async function deletePair(assistantMsgId: number) {
+  try {
+    await Prompt.deleteMessagePair(assistantMsgId)
+    const msgIdx = messages.value.findIndex((m) => m.id === assistantMsgId)
+    if (msgIdx >= 1) {
+      messages.value.splice(msgIdx - 1, 2)
+    }
+    naiveMessage.success("已删除")
+  } catch {
+    naiveMessage.error("删除失败，请重试")
+  }
+}
+
 function send() {
   const text = input.value.trim()
   if (!text || streaming.value) return
@@ -133,7 +197,6 @@ function renderContent(msg: { role: string; content: string }): string {
   return renderMarkdown(msg.content)
 }
 
-// Auto-scroll to bottom on new messages
 watch([() => messages.value.length, streamingContent], () => {
   nextTick(() => {
     if (messagesRef.value) {
@@ -289,4 +352,38 @@ watch([() => messages.value.length, streamingContent], () => {
   padding: 12px;
   border-top: 1px solid #e0e0e0;
 }
+
+.message-pair {
+  position: relative;
+  margin-bottom: 4px;
+}
+
+.message-pair .message {
+  margin-bottom: 16px;
+}
+
+.pair-delete-btn {
+  display: none;
+  position: absolute;
+  top: 0;
+  right: 0;
+  background: none;
+  border: 1px solid #e0e0e0;
+  border-radius: 4px;
+  padding: 3px 6px;
+  cursor: pointer;
+  color: #bbb;
+  line-height: 1;
+  transition: color 0.15s, border-color 0.15s;
+}
+
+.pair-delete-btn:hover {
+  color: #e03e3e;
+  border-color: #e03e3e;
+}
+
+.message-pair.has-delete:hover .pair-delete-btn {
+  display: inline-flex;
+  align-items: center;
+}
 </style>
diff --git a/src/pages/ChallengeDetail.vue b/src/pages/ChallengeDetail.vue
index 74682de..8437b43 100644
--- a/src/pages/ChallengeDetail.vue
+++ b/src/pages/ChallengeDetail.vue
@@ -183,13 +183,17 @@ async function loadChallenge() {
   assets.value = await TaskAssets.listChallenge(display)
   if (!authed.value) return
   connectPrompt(data.task_ptr)
-  setOnCodeComplete(async (code) => {
+  setOnCodeComplete(async (code, messageId) => {
     try {
-      await Submission.create(taskId.value, {
-        html: code.html ?? "",
-        css: code.css ?? "",
-        js: code.js ?? "",
-      })
+      await Submission.create(
+        taskId.value,
+        {
+          html: code.html ?? "",
+          css: code.css ?? "",
+          js: code.js ?? "",
+        },
+        messageId,
+      )
       message.success("已自动提交本次对话生成的代码")
     } catch {
       // 静默失败，不打扰用户
diff --git a/src/store/prompt.ts b/src/store/prompt.ts
index af4afaa..0da0781 100644
--- a/src/store/prompt.ts
+++ b/src/store/prompt.ts
@@ -5,6 +5,7 @@ import { html, css, js } from "./editors"
 export interface PromptMessage {
   role: "user" | "assistant"
   content: string
+  id?: number          // assistant message backend pk (for deletion)
   code?: { html: string | null; css: string | null; js: string | null }
   created?: string
 }
@@ -15,11 +16,10 @@ export const connected = ref(false)
 export const streaming = ref(false)
 export const streamingContent = ref("")
 let _onCodeComplete:
-  | ((code: {
-      html: string | null
-      css: string | null
-      js: string | null
-    }) => void)
+  | ((
+      code: { html: string | null; css: string | null; js: string | null },
+      messageId: number
+    ) => void)
   | null = null
 
 export function setOnCodeComplete(fn: typeof _onCodeComplete) {
@@ -45,14 +45,10 @@ export function connectPrompt(taskId: number) {
     if (data.type === "init") {
       streaming.value = false
       streamingContent.value = ""
-      // Skip overwriting messages if HTTP preload already loaded this conversation.
-      // If conversation_id differs (e.g. after "新对话"), always overwrite.
       const alreadyLoaded = conversationId.value === data.conversation_id
       conversationId.value = data.conversation_id
       if (!alreadyLoaded) {
         messages.value = data.messages || []
-        // Apply code from last assistant message if exists
-        // (skipped when HTTP preload already loaded and applied)
         const lastAssistant = [...messages.value]
           .reverse()
           .find((m) => m.role === "assistant" && m.code)
@@ -65,18 +61,17 @@ export function connectPrompt(taskId: number) {
       streamingContent.value += data.content
     } else if (data.type === "complete") {
       streaming.value = false
-      // Push the full assistant message
       messages.value.push({
         role: "assistant",
         content: streamingContent.value,
+        id: data.message_id,
         code: data.code,
       })
       streamingContent.value = ""
-      // Apply code to editors
       if (data.code) {
         applyCode(data.code)
         if (_onCodeComplete) {
-          _onCodeComplete(data.code)
+          _onCodeComplete(data.code, data.message_id)
         }
       }
     } else if (data.type === "error") {
@@ -115,7 +110,6 @@ export function sendPrompt(content: string, model: string = "") {
 }
 
 export function stopPrompt() {
-  // Remove the user message added to UI (not yet saved in DB)
   if (
     messages.value.length > 0 &&
     messages.value[messages.value.length - 1].role === "user"
@@ -124,7 +118,6 @@ export function stopPrompt() {
   }
   streaming.value = false
   streamingContent.value = ""
-  // connectPrompt closes old WS (triggering backend disconnect cleanup) then reconnects
   if (_currentTaskId) {
     connectPrompt(_currentTaskId)
   }