diff --git a/src/api/modules/game/room.ts b/src/api/modules/game/room.ts
index 08b1257..0b88d54 100644
--- a/src/api/modules/game/room.ts
+++ b/src/api/modules/game/room.ts
@@ -4,7 +4,9 @@ import type {
   CreateRoomResponse,
   GetRoomListRequest,
   GetRoomListResponse,
-  RoomDetailResponse
+  JoinRoomRequest,
+  RoomDetailResponse,
+  RoomItem
 } from './types'
 
 /**
@@ -37,6 +39,19 @@ export function createRoom(data: CreateRoomRequest) {
   return requestClient.post<CreateRoomResponse>('/game/room/create', data)
 }
 
+/**
+ * 加入房间
+ *
+ * 玩家通过此接口加入指定房间，成为房间内的玩家。
+ * 公开房间无需传密码。加入成功后需通过 WebSocket 进行后续交互。
+ *
+ * @param data - 加入房间参数（roomId 和可选的 password）
+ * @returns 更新后的房间信息
+ */
+export function joinRoom(data: JoinRoomRequest) {
+  return requestClient.post<RoomItem>('/game/room/join', data)
+}
+
 /**
  * 获取房间详情
  *
diff --git a/src/api/modules/game/types.ts b/src/api/modules/game/types.ts
index c12721b..0170348 100644
--- a/src/api/modules/game/types.ts
+++ b/src/api/modules/game/types.ts
@@ -151,6 +151,14 @@ export interface MoveItem {
   col: number
 }
 
+/** 加入房间请求参数 */
+export interface JoinRoomRequest {
+  /** 房间 ID */
+  roomId: string
+  /** 房间密码（可选，公开房间留空） */
+  password?: string
+}
+
 /** WebSocket 消息通用封装 */
 export interface WsMessage<T = unknown> {
   type: string
diff --git a/src/common/websocket/roomSocket.ts b/src/common/websocket/roomSocket.ts
index d1bba5b..28d1952 100644
--- a/src/common/websocket/roomSocket.ts
+++ b/src/common/websocket/roomSocket.ts
@@ -1,25 +1,40 @@
 import type { WsMessage } from '@/api/modules/game'
 
+/** 重连配置 */
+const RECONNECT_MAX_RETRIES = 5
+/** 重连基础延迟（ms），指数退避：1s, 2s, 4s, 8s, 16s */
+const RECONNECT_BASE_DELAY = 1000
+/** 重连最大延迟（ms） */
+const RECONNECT_MAX_DELAY = 16000
+
 /** WebSocket 连接回调 */
 export interface RoomSocketCallbacks {
   onOpen?: () => void
   onClose?: (event: CloseEvent) => void
   onError?: (event: Event) => void
   onMessage?: (message: WsMessage) => void
+  /** 自动重连成功回调（重连后需调用方重新拉取房间状态） */
+  onReconnect?: () => void
+  /** 重连次数耗尽回调 */
+  onReconnectFailed?: () => void
 }
 
 /** WebSocket 客户端封装 */
 export interface RoomSocket {
   /** 发送消息 */
   send: (type: string, data?: unknown) => void
-  /** 关闭连接 */
+  /** 关闭连接（主动关闭不触发重连） */
   close: () => void
   /** 连接状态 */
   isOpen: () => boolean
 }
 
 /**
- * 创建房间 WebSocket 连接
+ * 创建房间 WebSocket 连接（含自动重连）
+ *
+ * 连接断开时自动指数退避重连，最多重试 5 次。
+ * 主动调用 close() 或重连耗尽时触发 onClose 回调。
+ * 重连成功后触发 onReconnect 回调，调用方应在此重新拉取房间状态。
  *
  * @param roomId   房间 ID
  * @param token    用户认证 token
@@ -33,45 +48,113 @@ export function createRoomSocket(
 ): RoomSocket {
   const wsUrl = `${window.location.protocol === 'https:' ? 'wss:' : 'ws:'}//${window.location.host}/ws/room?roomId=${encodeURIComponent(roomId)}&token=${encodeURIComponent(token)}`
 
-  const ws = new WebSocket(wsUrl)
+  /** 当前 WebSocket 实例 */
+  let ws: WebSocket | null = null
+  /** 当前重试次数 */
+  let retryCount = 0
+  /** 是否主动关闭（主动关闭不重连） */
+  let intentionalClose = false
+  /** 重连定时器 ID，用于组件卸载时取消 */
+  let reconnectTimer: ReturnType<typeof setTimeout> | null = null
 
-  ws.onopen = () => {
-    // eslint-disable-next-line no-console
-    console.log('[WS] 房间连接已建立, roomId=', roomId)
-    callbacks.onOpen?.()
-  }
+  /** 建立 WebSocket 连接 */
+  function connect(): void {
+    // 如果已有旧的重连定时器，取消它
+    if (reconnectTimer) {
+      clearTimeout(reconnectTimer)
+      reconnectTimer = null
+    }
 
-  ws.onclose = (event) => {
-    // eslint-disable-next-line no-console
-    console.log('[WS] 房间连接已关闭, roomId=', roomId, 'code=', event.code)
-    callbacks.onClose?.(event)
-  }
+    ws = new WebSocket(wsUrl)
 
-  ws.onerror = (event) => {
-    console.error('[WS] 房间连接错误, roomId=', roomId, event)
-    callbacks.onError?.(event)
-  }
+    ws.onopen = () => {
+      // eslint-disable-next-line no-console
+      console.log('[WS] 房间连接已建立, roomId=', roomId)
+      if (retryCount > 0) {
+        // 这是重连成功
+        // eslint-disable-next-line no-console
+        console.log('[WS] 重连成功, roomId=', roomId, '重试次数=', retryCount)
+        retryCount = 0
+        callbacks.onReconnect?.()
+      } else {
+        callbacks.onOpen?.()
+      }
+    }
 
-  ws.onmessage = (event) => {
-    try {
-      const message: WsMessage = JSON.parse(event.data as string)
-      callbacks.onMessage?.(message)
-    } catch (e) {
-      console.error('[WS] 消息解析失败:', e)
+    ws.onclose = (event) => {
+      // 主动关闭，不重连
+      if (intentionalClose) {
+        // eslint-disable-next-line no-console
+        console.log('[WS] 主动关闭连接, roomId=', roomId, 'code=', event.code)
+        callbacks.onClose?.(event)
+        return
+      }
+
+      // 已达最大重试次数
+      if (retryCount >= RECONNECT_MAX_RETRIES) {
+        // eslint-disable-next-line no-console
+        console.log('[WS] 重连次数耗尽, roomId=', roomId, 'retries=', retryCount)
+        callbacks.onReconnectFailed?.()
+        callbacks.onClose?.(event)
+        return
+      }
+
+      // 指数退避重连
+      retryCount++
+      const delay = Math.min(
+        RECONNECT_BASE_DELAY * Math.pow(2, retryCount - 1),
+        RECONNECT_MAX_DELAY
+      )
+      // eslint-disable-next-line no-console
+      console.log(
+        `[WS] 连接断开，${delay / 1000}s 后重连 (${retryCount}/${RECONNECT_MAX_RETRIES}), roomId=`,
+        roomId
+      )
+
+      reconnectTimer = setTimeout(() => {
+        reconnectTimer = null
+        connect()
+      }, delay)
+    }
+
+    ws.onerror = (event) => {
+      console.error('[WS] 连接错误, roomId=', roomId, event)
+      callbacks.onError?.(event)
+    }
+
+    ws.onmessage = (event) => {
+      try {
+        const message: WsMessage = JSON.parse(event.data as string)
+        callbacks.onMessage?.(message)
+      } catch (e) {
+        console.error('[WS] 消息解析失败:', e)
+      }
     }
   }
 
+  // 初始连接
+  connect()
+
   return {
     send(type: string, data?: unknown) {
-      if (ws.readyState === WebSocket.OPEN) {
+      if (ws && ws.readyState === WebSocket.OPEN) {
         ws.send(JSON.stringify({ type, data }))
       }
     },
     close() {
-      ws.close(1000, '用户离开')
+      intentionalClose = true
+      // 取消进行中的重连定时器
+      if (reconnectTimer) {
+        clearTimeout(reconnectTimer)
+        reconnectTimer = null
+      }
+      if (ws) {
+        ws.close(1000, '用户离开')
+        ws = null
+      }
     },
     isOpen() {
-      return ws.readyState === WebSocket.OPEN
+      return ws?.readyState === WebSocket.OPEN
     }
   }
 }
diff --git a/src/components/baseLayouts/Lobby.vue b/src/components/baseLayouts/Lobby.vue
index bfc5748..6b723a3 100644
--- a/src/components/baseLayouts/Lobby.vue
+++ b/src/components/baseLayouts/Lobby.vue
@@ -51,8 +51,9 @@ import { useRouter } from 'vue-router'
 import type { RoomItem } from '@/api/modules/game'
 import { useBaseLayoutStore } from '@/stores'
 import { storeToRefs } from 'pinia'
-import { getRoomList } from '@/api/modules/game'
+import { getRoomList, joinRoom } from '@/api/modules/game'
 import { sseBus } from '@/stores/sseBus'
+import { ElMessage } from 'element-plus'
 
 /** 状态筛选选项 */
 const statusFilters = [
@@ -129,17 +130,26 @@ const filteredRooms = computed(() => {
   return list
 })
 
-/** 加入房间 */
-function handleJoin(roomId: string) {
-  router.push(`/room/${roomId}`)
+/** 加入房间（需先调用后端 join API 成为玩家） */
+async function handleJoin(roomId: string) {
+  try {
+    await joinRoom({ roomId })
+    router.push(`/room/${roomId}`)
+  } catch (e: unknown) {
+    // 后端业务错误通过 ApiResponse.message 传递，需兼容多种 reject 类型
+    const msg =
+      (e as { message?: string })?.message ||
+      (e instanceof Error ? e.message : '加入房间失败，请稍后重试')
+    ElMessage.error(msg)
+  }
 }
 
-/** 加入指定座位 */
-function handleJoinSeat(roomId: string, seatIndex: number) {
-  router.push({ path: `/room/${roomId}`, query: { seat: String(seatIndex) } })
+/** 加入指定座位（后端自动分配座位，调用 join API 即可） */
+async function handleJoinSeat(roomId: string, _seatIndex: number) {
+  await handleJoin(roomId)
 }
 
-/** 观战 */
+/** 观战（不调用 join API，仅建立 WebSocket 连接接收对局数据） */
 function handleSpectate(roomId: string) {
   router.push(`/room/${roomId}`)
 }
diff --git a/src/views/game/RoomPage.vue b/src/views/game/RoomPage.vue
index ce6aa31..b66cdba 100644
--- a/src/views/game/RoomPage.vue
+++ b/src/views/game/RoomPage.vue
@@ -76,12 +76,26 @@ onMounted(async () => {
     const res = await getRoomDetail(roomId)
     roomStore.initFromDetail(res.data, userId)
 
-    // 2. 建立 WebSocket 连接
+    // 2. 建立 WebSocket 连接（含自动重连）
     const token = accountStore.accessToken
     socket = createRoomSocket(roomId, token, {
       onMessage: handleWsMessage,
-      onClose: () => {
-        // 连接关闭，提示并返回大厅
+      /**
+       * 重连成功 → 重新拉取房间详情恢复完整状态（棋盘、轮次、玩家列表等）
+       */
+      onReconnect: async () => {
+        try {
+          const res = await getRoomDetail(roomId)
+          roomStore.initFromDetail(res.data, userId)
+        } catch {
+          // 重连后拉取房间状态失败（房间可能已结束），返回大厅
+          router.push('/')
+        }
+      },
+      /**
+       * 重连次数耗尽 → 返回大厅
+       */
+      onReconnectFailed: () => {
         router.push('/')
       }
     })