diff --git a/src/views/im/home/components/PagedScroller.vue b/src/views/im/home/components/PagedScroller.vue
index f3561efe2..c970d48a3 100644
--- a/src/views/im/home/components/PagedScroller.vue
+++ b/src/views/im/home/components/PagedScroller.vue
@@ -5,7 +5,12 @@
     - 通过 slot 暴露每一项，让调用方自己决定渲染
   -->
   <el-scrollbar ref="scrollbarRef" class="w-full h-full">
-    <slot v-for="(item, idx) in displayItems" :item="item" :index="idx" :key="idx"></slot>
+    <slot
+      v-for="(item, idx) in displayItems"
+      :item="item"
+      :index="idx"
+      :key="resolveItemKey(item, idx)"
+    ></slot>
     <div
       v-if="showFooter"
       class="py-3 text-xs text-center text-[var(--el-text-color-secondary)]"
@@ -26,6 +31,7 @@ const props = withDefaults(
     items: T[] // 全量数据
     pageSize?: number // 每页渲染条数
     threshold?: number // 距底多少 px 触发下一页
+    itemKey?: string // 业务 id 字段名（如 'userId' / 'id'）；不传 / 字段值非 string|number 时回退 idx
   }>(),
   {
     pageSize: 30,
@@ -33,6 +39,15 @@ const props = withDefaults(
   }
 )
 
+/** 解析每条 item 的 :key：caller 传 itemKey 则按字段取，无效 / 缺失回退索引，避免传错字段时全表 undefined key */
+function resolveItemKey(item: T, idx: number): string | number {
+  if (!props.itemKey || item == null || typeof item !== 'object') {
+    return idx
+  }
+  const value = (item as Record<string, unknown>)[props.itemKey]
+  return typeof value === 'string' || typeof value === 'number' ? value : idx
+}
+
 const scrollbarRef = useTemplateRef<InstanceType<typeof ElScrollbar>>('scrollbarRef')
 const page = ref(1)
 
diff --git a/src/views/im/home/components/picker/GroupMemberPickerPanel.vue b/src/views/im/home/components/picker/GroupMemberPickerPanel.vue
index e47511155..ecb948be2 100644
--- a/src/views/im/home/components/picker/GroupMemberPickerPanel.vue
+++ b/src/views/im/home/components/picker/GroupMemberPickerPanel.vue
@@ -21,7 +21,7 @@
       </div>
 
       <div class="flex-1 min-h-0">
-        <PagedScroller :items="shownMembers" :page-size="30">
+        <PagedScroller :items="shownMembers" :page-size="30" item-key="userId">
           <template #default="{ item }">
             <GroupMemberItem
               :member="(item as GroupMemberLite)"
diff --git a/src/views/im/home/composables/useMessagePuller.ts b/src/views/im/home/composables/useMessagePuller.ts
index 04519da9e..707244fba 100644
--- a/src/views/im/home/composables/useMessagePuller.ts
+++ b/src/views/im/home/composables/useMessagePuller.ts
@@ -31,6 +31,7 @@ import {
 } from '../../utils/config'
 import { useUserStore } from '@/store/modules/user'
 import { buildChannelConversationStub } from '../../utils/channel'
+import { getPrivateMessagePeerId } from '../../utils/message'
 import type { Message } from '../types'
 
 /**
@@ -52,11 +53,11 @@ export const useMessagePuller = () => {
   const groupStore = useGroupStore()
   const currentUserId = Number(userStore.getUser?.id) || 0
 
-  /** 私聊会话归属：自己发的算"发给 receiverId 的会话"，否则算"发送方的会话" */
+  /** 私聊会话归属：自己发的算"发给 receiverId 的会话"，否则算"发送方的会话"；curry currentUserId 进闭包减少 3 处调用方的样板 */
   const getPrivatePeerId = (message: ImPrivateMessageRespVO) =>
-    message.senderId === currentUserId ? message.receiverId : message.senderId
+    getPrivateMessagePeerId(message, currentUserId)
 
-  /** 服务端私聊消息 -> 本地 Message */
+  /** 服务端私聊消息 -> 本地 Message：targetId 是会话主键（对端 userId） */
   const convertPrivateMessage = (message: ImPrivateMessageRespVO): Message => {
     return {
       id: message.id,
@@ -66,7 +67,7 @@ export const useMessagePuller = () => {
       status: message.status,
       sendTime: new Date(message.sendTime).getTime(),
       senderId: message.senderId,
-      targetId: message.receiverId,
+      targetId: getPrivatePeerId(message),
       selfSend: message.senderId === currentUserId
     }
   }
diff --git a/src/views/im/home/pages/conversation/components/message/MessageReadStatus.vue b/src/views/im/home/pages/conversation/components/message/MessageReadStatus.vue
index 93353e386..282ffa972 100644
--- a/src/views/im/home/pages/conversation/components/message/MessageReadStatus.vue
+++ b/src/views/im/home/pages/conversation/components/message/MessageReadStatus.vue
@@ -23,7 +23,7 @@
 
     <el-tabs v-model="activeTab" stretch>
       <el-tab-pane :label="`已读(${readMembers.length})`" name="read">
-        <PagedScroller :items="readMembers" :page-size="20" class="h-75">
+        <PagedScroller :items="readMembers" :page-size="20" item-key="userId" class="h-75">
           <template #default="{ item }">
             <GroupMember :member="item as GroupMemberLite" :height="40" :clickable="false" />
           </template>
@@ -36,7 +36,7 @@
         </div>
       </el-tab-pane>
       <el-tab-pane :label="`未读(${unreadMembers.length})`" name="unread">
-        <PagedScroller :items="unreadMembers" :page-size="20" class="h-75">
+        <PagedScroller :items="unreadMembers" :page-size="20" item-key="userId" class="h-75">
           <template #default="{ item }">
             <GroupMember :member="item as GroupMemberLite" :height="40" :clickable="false" />
           </template>
diff --git a/src/views/im/home/store/websocketStore.ts b/src/views/im/home/store/websocketStore.ts
index 0c9595ca0..0792d1aed 100644
--- a/src/views/im/home/store/websocketStore.ts
+++ b/src/views/im/home/store/websocketStore.ts
@@ -14,7 +14,11 @@ import {
   isGroupRequestNotification,
   isNormalMessage
 } from '../../utils/constants'
-import { playAudioTip, resolveCallEndReasonText } from '../../utils/message'
+import {
+  getPrivateMessagePeerId,
+  playAudioTip,
+  resolveCallEndReasonText
+} from '../../utils/message'
 import { MESSAGE_PRIVATE_READ_ENABLED, MESSAGE_GROUP_READ_ENABLED } from '../../utils/config'
 import { useConversationStore } from './conversationStore'
 import { useFriendStore, type FriendNotificationPayload } from './friendStore'
@@ -54,7 +58,7 @@ const isFriendDeleteWithClear = (frame: ImPrivateMessageDTO): boolean => {
 }
 
 /**
- * WebSocket 私聊 DTO -> 前端 Message
+ * WebSocket 私聊 DTO -> 前端 Message；targetId 是会话主键（对端 userId）
  * 不写发送人名字段：渲染层走 utils/user 实时算（备注 / 群昵称变更后历史消息自动刷新）
  */
 const convertPrivateMessage = (
@@ -68,7 +72,7 @@ const convertPrivateMessage = (
   status: websocketMessage.status,
   sendTime: new Date(websocketMessage.sendTime).getTime(),
   senderId: websocketMessage.senderId,
-  targetId: websocketMessage.receiverId,
+  targetId: getPrivateMessagePeerId(websocketMessage, currentUserId),
   selfSend: websocketMessage.senderId === currentUserId
 })
 
@@ -442,7 +446,7 @@ export const useImWebSocketStore = defineStore('imWebSocketStore', {
       const friendStore = useFriendStore()
       const currentUserId = Number(userStore.getUser?.id) || 0
       const selfSend = websocketMessage.senderId === currentUserId
-      const peerId = selfSend ? websocketMessage.receiverId : websocketMessage.senderId
+      const peerId = getPrivateMessagePeerId(websocketMessage, currentUserId)
       // 未知对端（陌生人加好友前先收到消息等场景）：异步补拉一次，下次再渲染就有 name/avatar
       const friend = friendStore.getFriend(peerId)
       if (!friend) {
@@ -640,7 +644,7 @@ export const useImWebSocketStore = defineStore('imWebSocketStore', {
     computeFriendPeerId(frame: ImPrivateMessageDTO): number {
       const userStore = useUserStore()
       const currentUserId = Number(userStore.getUser?.id) || 0
-      return frame.senderId === currentUserId ? frame.receiverId : frame.senderId
+      return getPrivateMessagePeerId(frame, currentUserId)
     },
 
     /**
diff --git a/src/views/im/home/types/index.ts b/src/views/im/home/types/index.ts
index 077b7eb3a..ae0fe20b9 100644
--- a/src/views/im/home/types/index.ts
+++ b/src/views/im/home/types/index.ts
@@ -83,7 +83,7 @@ export interface Message {
   // ========== 前端扩展字段 ==========
   // 发送人显示名一律渲染时实时算：utils/user.getSenderDisplayName / getSenderRealNickname
   // 不在 Message 上存任何名字快照，避免备注 / 群昵称变更后历史消息显示陈旧
-  targetId: number // 会话目标编号（私聊=receiverId / 群聊=groupId），与 Conversation.targetId 一致
+  targetId: number // 会话目标编号（私聊=对端 userId / 群聊=groupId），与 Conversation.targetId 一致
   selfSend: boolean // 是否自己发送（前端按 senderId 计算）
   uploadProgress?: number // 媒体消息上传进度（0-100）；status=SENDING 期间持续更新；ack 后置 undefined
   // 媒体消息内存中保留的原始 File；下划线前缀表示不进 JSON / 不持久化（IDB 恢复后必为 undefined）
diff --git a/src/views/im/utils/message.ts b/src/views/im/utils/message.ts
index 7d8b5d8fd..5a14bf294 100644
--- a/src/views/im/utils/message.ts
+++ b/src/views/im/utils/message.ts
@@ -28,6 +28,21 @@ export const generateClientMessageId = (): string => {
   return generateUUID()
 }
 
+// ==================== 私聊对端 userId ====================
+
+/**
+ * 私聊消息 / DTO 的对端 userId：自己发的对端是 receiver，别人发的对端是 sender
+ *
+ * 收口 4 处旧 inline（websocketStore.convertPrivateMessage / handlePrivateMessage / computeFriendPeerId
+ * 和 useMessagePuller.getPrivatePeerId），结构类型只要 senderId / receiverId 两个字段，REST 与 WS DTO 都满足
+ */
+export function getPrivateMessagePeerId(
+  message: { senderId: number; receiverId: number },
+  currentUserId: number
+): number {
+  return message.senderId === currentUserId ? message.receiverId : message.senderId
+}
+
 // ==================== 文本片段（tip 文案 + TEXT 气泡共用） ====================
 // 既用于灰条 tip（"XX 邀请 YY 加入群聊"），也用于 TEXT 气泡正文（@xxx 高亮 + URL 自动识别）。
 // mention 段携带 userId 用于挂点击弹 UserInfoCard；link 段携带 href 用于 <a> 跳转；