diff --git a/backend/internal/modules/chat/adapter.go b/backend/internal/modules/chat/adapter.go
new file mode 100644
index 0000000..17907e2
--- /dev/null
+++ b/backend/internal/modules/chat/adapter.go
@@ -0,0 +1,24 @@
+package chat
+
+import (
+	"gorm.io/gorm"
+	"hfb_sys/backend/internal/model"
+)
+
+// ListingChatCreatorAdapter 适配器,实现 listing.ListingChatCreator 接口
+type ListingChatCreatorAdapter struct {
+	// 无需字段,直接调用包级函数
+}
+
+func NewListingChatCreatorAdapter() *ListingChatCreatorAdapter {
+	return &ListingChatCreatorAdapter{}
+}
+
+// EnsureListingConversation 实现接口
+func (a *ListingChatCreatorAdapter) EnsureListingConversation(tx *gorm.DB, listing model.RentalListing) (uint64, error) {
+	conv, err := EnsureListingConversation(tx, listing)
+	if err != nil {
+		return 0, err
+	}
+	return conv.ID, nil
+}
diff --git a/backend/internal/modules/chat/listing_group.go b/backend/internal/modules/chat/listing_group.go
new file mode 100644
index 0000000..2040f97
--- /dev/null
+++ b/backend/internal/modules/chat/listing_group.go
@@ -0,0 +1,319 @@
+package chat
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+	"hfb_sys/backend/internal/model"
+)
+
+// 会话类型常量
+const (
+	ConversationTypeOrderGroup   = "order_group"
+	ConversationTypeListingGroup = "listing_group"
+	ConversationTypeGeneralSupport = "general_support"
+)
+
+var (
+	ErrListingConversationExists = errors.New("发布群已存在")
+)
+
+// EnsureListingConversation 确保发布群存在(幂等)
+func EnsureListingConversation(tx *gorm.DB, listing model.RentalListing) (*model.ChatConversation, error) {
+	// 1. 幂等查重
+	var existing model.ChatConversation
+	err := tx.Where("listing_id = ?", listing.ID).First(&existing).Error
+	if err == nil {
+		return &existing, nil
+	}
+	if !errors.Is(err, gorm.ErrRecordNotFound) {
+		return nil, err
+	}
+
+	// 2. 建会话
+	now := time.Now()
+	conversation := model.ChatConversation{
+		ListingID: &listing.ID,
+		Type:      ConversationTypeListingGroup,
+		Title:     listingConversationTitle(listing),
+		Status:    "active",
+	}
+	if err := tx.Create(&conversation).Error; err != nil {
+		return nil, err
+	}
+
+	// 3. 写参与者: 号主 + 客服
+	participants := []model.ChatParticipant{
+		{
+			ConversationID:  conversation.ID,
+			ParticipantType: "user",
+			ParticipantID:   listing.OwnerID,
+			Role:            "owner",
+			JoinedAt:        now,
+		},
+	}
+
+	// 获取客服
+	if supportID := defaultSupportAdminID(tx); supportID > 0 {
+		participants = append(participants, model.ChatParticipant{
+			ConversationID:  conversation.ID,
+			ParticipantType: "admin",
+			ParticipantID:   supportID,
+			Role:            "support",
+			JoinedAt:        now,
+		})
+	}
+
+	for _, participant := range participants {
+		if err := tx.Clauses(clause.OnConflict{DoNothing: true}).Create(&participant).Error; err != nil {
+			return nil, err
+		}
+	}
+
+	// 4. 取二维码(带行锁)
+	var qrcode *model.ChatQrCode
+	var qrcodeImageURL string
+	qrcodeObj, err := fetchUnusedQrCode(tx)
+	if err != nil {
+		return nil, err
+	}
+	if qrcodeObj != nil {
+		qrcode = qrcodeObj
+		qrcodeImageURL = qrcode.ImageURL
+		// 标记二维码为已使用
+		if err := markQrCodeAsUsed(tx, qrcode.ID, conversation.ID); err != nil {
+			return nil, err
+		}
+	}
+
+	// 5. 发欢迎语
+	welcomeMessage := getListingGroupWelcomeMessage(tx)
+	if err := sendSystemMessage(tx, conversation.ID, welcomeMessage); err != nil {
+		return nil, err
+	}
+
+	// 6. 发二维码图片(如果有)
+	if qrcodeImageURL != "" {
+		if err := sendQrCodeImage(tx, conversation.ID, qrcodeImageURL); err != nil {
+			return nil, err
+		}
+	} else {
+		// 无二维码,发提示
+		noQrTip := "客服企业微信群二维码补充中，请稍后在群内关注"
+		if err := sendSystemMessage(tx, conversation.ID, noQrTip); err != nil {
+			return nil, err
+		}
+	}
+
+	// 7. 库存预警检查
+	if qrcode != nil {
+		if err := checkQrCodeStockAndAlert(tx, &conversation); err != nil {
+			// 预警失败不阻塞建群,仅记录日志
+			// TODO: 添加日志
+		}
+	}
+
+	return &conversation, nil
+}
+
+// AddRenterToListingConversation 拉租客进发布群
+func AddRenterToListingConversation(tx *gorm.DB, listingID uint64, renterID uint64, orderNo string) error {
+	// 1. 查找发布群
+	var conv model.ChatConversation
+	err := tx.Where("listing_id = ?", listingID).First(&conv).Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			// 历史数据无发布群,优雅跳过
+			return nil
+		}
+		return err
+	}
+
+	// 2. 幂等插入租客
+	now := time.Now()
+	participant := model.ChatParticipant{
+		ConversationID:  conv.ID,
+		ParticipantType: "user",
+		ParticipantID:   renterID,
+		Role:            "renter",
+		JoinedAt:        now, // 关键: 记录加入时间,用于消息可见性过滤
+	}
+
+	if err := tx.Clauses(clause.OnConflict{DoNothing: true}).Create(&participant).Error; err != nil {
+		return err
+	}
+
+	// 3. 发系统消息
+	message := "租客已加入群聊(订单 " + orderNo + ")"
+	return sendSystemMessage(tx, conv.ID, message)
+}
+
+// RemoveRenterFromListingConversation 移出租客
+func RemoveRenterFromListingConversation(tx *gorm.DB, listingID uint64, renterID uint64) error {
+	// 1. 查找发布群
+	var conv model.ChatConversation
+	err := tx.Where("listing_id = ?", listingID).First(&conv).Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			// 无发布群,跳过
+			return nil
+		}
+		return err
+	}
+
+	// 2. 删除租客参与者记录
+	result := tx.Where("conversation_id = ? AND participant_type = ? AND participant_id = ? AND role = ?",
+		conv.ID, "user", renterID, "renter").
+		Delete(&model.ChatParticipant{})
+
+	if result.Error != nil {
+		return result.Error
+	}
+
+	// 3. 发系统消息(如果确实删除了)
+	if result.RowsAffected > 0 {
+		message := "订单已结束，租客已退出群聊"
+		return sendSystemMessage(tx, conv.ID, message)
+	}
+
+	return nil
+}
+
+// 辅助函数
+
+func listingConversationTitle(listing model.RentalListing) string {
+	return "账号群 " + listing.ListingNo
+}
+
+func getListingGroupWelcomeMessage(tx *gorm.DB) string {
+	defaultMsg := "欢迎加入账号群！请号主扫描下方二维码加入企业微信群，方便客服与您及时联系。"
+
+	var cfg model.SystemConfig
+	if err := tx.Where("`key` = ?", "chat.listing_group_welcome").First(&cfg).Error; err == nil && cfg.Value != "" {
+		return cfg.Value
+	}
+
+	return defaultMsg
+}
+
+func sendSystemMessage(tx *gorm.DB, conversationID uint64, content string) error {
+	message := model.ChatMessage{
+		ConversationID: conversationID,
+		SenderType:     "system",
+		SenderRole:     "system",
+		ContentType:    "system",
+		Content:        content,
+		AttachmentURLS: emptyJSONList(),
+	}
+
+	if err := tx.Create(&message).Error; err != nil {
+		return err
+	}
+
+	// 更新会话的最后消息
+	return updateConversationLastMessage(tx, conversationID, &message)
+}
+
+func sendQrCodeImage(tx *gorm.DB, conversationID uint64, imageURL string) error {
+	attachmentURLs := `["` + imageURL + `"]`
+	content := "👇 请扫码加入企业微信群"
+
+	message := model.ChatMessage{
+		ConversationID: conversationID,
+		SenderType:     "system",
+		SenderRole:     "system",
+		ContentType:    "image",
+		Content:        content,
+		AttachmentURLS: []byte(attachmentURLs),
+	}
+
+	if err := tx.Create(&message).Error; err != nil {
+		return err
+	}
+
+	// 更新会话的最后消息
+	return updateConversationLastMessage(tx, conversationID, &message)
+}
+
+func updateConversationLastMessage(tx *gorm.DB, conversationID uint64, message *model.ChatMessage) error {
+	updates := map[string]interface{}{
+		"last_message_id":      message.ID,
+		"last_message_preview": truncatePreview(message.Content),
+		"last_message_at":      message.CreatedAt,
+	}
+
+	return tx.Model(&model.ChatConversation{}).
+		Where("id = ?", conversationID).
+		Updates(updates).Error
+}
+
+func fetchUnusedQrCode(tx *gorm.DB) (*model.ChatQrCode, error) {
+	var qrcode model.ChatQrCode
+	now := time.Now()
+
+	err := tx.Where("status = ?", QrCodeStatusUnused).
+		Where("expires_at IS NULL OR expires_at > ?", now).
+		Order("id ASC").
+		Limit(1).
+		Clauses(clause.Locking{Strength: "UPDATE"}).
+		First(&qrcode).Error
+
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, nil // 无可用二维码,返回 nil 而非错误
+		}
+		return nil, err
+	}
+
+	return &qrcode, nil
+}
+
+func markQrCodeAsUsed(tx *gorm.DB, qrcodeID uint64, conversationID uint64) error {
+	now := time.Now()
+	return tx.Model(&model.ChatQrCode{}).
+		Where("id = ?", qrcodeID).
+		Updates(map[string]interface{}{
+			"status":          QrCodeStatusUsed,
+			"conversation_id": conversationID,
+			"used_at":         now,
+		}).Error
+}
+
+func checkQrCodeStockAndAlert(tx *gorm.DB, conversation *model.ChatConversation) error {
+	// 获取库存阈值
+	threshold := int64(5)
+	var cfg model.SystemConfig
+	if err := tx.Where("`key` = ?", "chat.qrcode_low_stock_threshold").First(&cfg).Error; err == nil && cfg.Value != "" {
+		// 尝试解析为数字
+		if val, err := parseThreshold(cfg.Value); err == nil {
+			threshold = val
+		}
+	}
+
+	// 统计未使用的二维码数量
+	var count int64
+	if err := tx.Model(&model.ChatQrCode{}).
+		Where("status = ?", QrCodeStatusUnused).
+		Count(&count).Error; err != nil {
+		return err
+	}
+
+	// 如果低于阈值,发送预警给所有客服
+	if count <= threshold {
+		// TODO: 发送站内信给所有 cs 角色客服
+		// 需要 notification 模块支持
+	}
+
+	return nil
+}
+
+func parseThreshold(value string) (int64, error) {
+	var threshold int64
+	if _, err := fmt.Sscanf(value, "%d", &threshold); err != nil {
+		return 0, err
+	}
+	return threshold, nil
+}
diff --git a/backend/internal/modules/chat/message.go b/backend/internal/modules/chat/message.go
index ae2bd05..34ae252 100644
--- a/backend/internal/modules/chat/message.go
+++ b/backend/internal/modules/chat/message.go
@@ -14,11 +14,15 @@ func (r *Repository) Messages(ctx context.Context, principal Principal, conversa
 	page, pageSize = normalizePagination(page, pageSize)
 	db := r.db.WithContext(ctx)
 
+	var participant *model.ChatParticipant
+
 	// 管理员可以查看任意会话的消息，普通用户需要是 participant
 	if principal.Type != "admin" {
-		if _, err := r.findParticipant(db, principal, conversationID, false); err != nil {
+		p, err := r.findParticipant(db, principal, conversationID, false)
+		if err != nil {
 			return nil, err
 		}
+		participant = p
 	} else {
 		// 管理员需要验证会话存在
 		var count int64
@@ -30,14 +34,22 @@ func (r *Repository) Messages(ctx context.Context, principal Principal, conversa
 		}
 	}
 
+	// 构建查询
+	query := db.Model(&model.ChatMessage{}).Where("conversation_id = ?", conversationID)
+
+	// 租客只能看到加入时间之后的消息
+	if principal.Type == "user" && participant != nil && participant.Role == "renter" {
+		query = query.Where("created_at >= ?", participant.JoinedAt)
+	}
+
 	var total int64
-	if err := db.Model(&model.ChatMessage{}).Where("conversation_id = ?", conversationID).Count(&total).Error; err != nil {
+	if err := query.Count(&total).Error; err != nil {
 		return nil, err
 	}
+
 	offset := (page - 1) * pageSize
 	var rows []model.ChatMessage
-	if err := db.Where("conversation_id = ?", conversationID).
-		Order("id ASC").
+	if err := query.Order("id ASC").
 		Offset(offset).
 		Limit(pageSize).
 		Find(&rows).Error; err != nil {
diff --git a/backend/internal/modules/listing/dto.go b/backend/internal/modules/listing/dto.go
index 69a2007..ef7ffb1 100644
--- a/backend/internal/modules/listing/dto.go
+++ b/backend/internal/modules/listing/dto.go
@@ -9,32 +9,33 @@ import (
 )
 
 type ListingDTO struct {
-	ID                uint64         `json:"id"`
-	ListingNo         string         `json:"listing_no"`
-	AccountID         uint64         `json:"account_id"`
-	OwnerID           uint64         `json:"owner_id"`
-	OwnerPhone        string         `json:"owner_phone,omitempty"`
-	OwnerNickname     string         `json:"owner_nickname,omitempty"`
-	Title             string         `json:"title"`
-	Description       string         `json:"description"`
-	GameName          string         `json:"game_name"`
-	ServerRegion      string         `json:"server_region"`
-	LoginPlatform     string         `json:"login_platform"`
-	RankLevel         string         `json:"rank_level"`
-	HafCoinAmount     int64          `json:"haf_coin_amount"`
-	AssetSummary      map[string]any `json:"asset_summary,omitempty"`
-	ScreenshotURLS    []string       `json:"screenshot_urls"`
-	CoverURL          string         `json:"cover_url"`
-	PriceCent         int64          `json:"price_cent"`
-	DepositAmountCent int64          `json:"deposit_amount_cent"`
-	IsAccelerated     bool           `json:"is_accelerated_sale"`
-	InTransaction     bool           `json:"in_transaction"`
-	Status            string         `json:"status"`
-	ReviewStatus      string         `json:"review_status"`
-	ReviewReason      string         `json:"review_reason"`
-	PublishedAt       *time.Time     `json:"published_at"`
-	CreatedAt         time.Time      `json:"created_at"`
-	UpdatedAt         time.Time      `json:"updated_at"`
+	ID                          uint64         `json:"id"`
+	ListingNo                   string         `json:"listing_no"`
+	AccountID                   uint64         `json:"account_id"`
+	OwnerID                     uint64         `json:"owner_id"`
+	OwnerPhone                  string         `json:"owner_phone,omitempty"`
+	OwnerNickname               string         `json:"owner_nickname,omitempty"`
+	Title                       string         `json:"title"`
+	Description                 string         `json:"description"`
+	GameName                    string         `json:"game_name"`
+	ServerRegion                string         `json:"server_region"`
+	LoginPlatform               string         `json:"login_platform"`
+	RankLevel                   string         `json:"rank_level"`
+	HafCoinAmount               int64          `json:"haf_coin_amount"`
+	AssetSummary                map[string]any `json:"asset_summary,omitempty"`
+	ScreenshotURLS              []string       `json:"screenshot_urls"`
+	CoverURL                    string         `json:"cover_url"`
+	PriceCent                   int64          `json:"price_cent"`
+	DepositAmountCent           int64          `json:"deposit_amount_cent"`
+	IsAccelerated               bool           `json:"is_accelerated_sale"`
+	InTransaction               bool           `json:"in_transaction"`
+	Status                      string         `json:"status"`
+	ReviewStatus                string         `json:"review_status"`
+	ReviewReason                string         `json:"review_reason"`
+	PublishedAt                 *time.Time     `json:"published_at"`
+	ListingGroupConversationID  uint64         `json:"listing_group_conversation_id,omitempty"`
+	CreatedAt                   time.Time      `json:"created_at"`
+	UpdatedAt                   time.Time      `json:"updated_at"`
 }
 
 type CreateRequest struct {
diff --git a/backend/internal/modules/listing/mutation.go b/backend/internal/modules/listing/mutation.go
index 84776c5..6b4b15e 100644
--- a/backend/internal/modules/listing/mutation.go
+++ b/backend/internal/modules/listing/mutation.go
@@ -59,7 +59,19 @@ func (r *Repository) Create(ctx context.Context, ownerID uint64, req CreateReque
 		if err := tx.Create(&listing).Error; err != nil {
 			return err
 		}
+
+		// 发布提交时建发布群
+		var conversationID uint64
+		if r.chatCreator != nil {
+			convID, err := r.chatCreator.EnsureListingConversation(tx, listing)
+			if err != nil {
+				return err
+			}
+			conversationID = convID
+		}
+
 		dto = toDTO(account, listing)
+		dto.ListingGroupConversationID = conversationID
 		return nil
 	})
 	return dto, err
diff --git a/backend/internal/modules/listing/repository.go b/backend/internal/modules/listing/repository.go
index 26d1551..44cb330 100644
--- a/backend/internal/modules/listing/repository.go
+++ b/backend/internal/modules/listing/repository.go
@@ -6,16 +6,26 @@ import (
 	"time"
 
 	"gorm.io/gorm"
+	"hfb_sys/backend/internal/model"
 )
 
+// ListingChatCreator 发布群创建接口(由 chat 模块实现,避免直接依赖)
+type ListingChatCreator interface {
+	EnsureListingConversation(tx *gorm.DB, listing model.RentalListing) (conversationID uint64, err error)
+}
+
 type Repository struct {
 	db                 *gorm.DB
 	publicZoneCountsMu sync.Mutex
 	publicZoneCounts   publicZoneCountCache
+	chatCreator        ListingChatCreator
 }
 
-func NewRepository(db *gorm.DB) *Repository {
-	return &Repository{db: db}
+func NewRepository(db *gorm.DB, chatCreator ListingChatCreator) *Repository {
+	return &Repository{
+		db:          db,
+		chatCreator: chatCreator,
+	}
 }
 
 type publicZoneCountCache struct {
diff --git a/backend/internal/modules/order/checkout_finalize.go b/backend/internal/modules/order/checkout_finalize.go
index 0e08ca6..c2341f5 100644
--- a/backend/internal/modules/order/checkout_finalize.go
+++ b/backend/internal/modules/order/checkout_finalize.go
@@ -4,6 +4,7 @@ import (
 	"time"
 
 	"hfb_sys/backend/internal/model"
+	"hfb_sys/backend/internal/modules/chat"
 	"hfb_sys/backend/internal/modules/notification"
 	"hfb_sys/backend/internal/modules/wallet"
 
@@ -38,6 +39,13 @@ func (r *Repository) finalizeCheckout(tx *gorm.DB, order *model.RentalOrder, che
 	if err := saveFinalizedCheckout(tx, order, checkout, listing, account); err != nil {
 		return nil, err
 	}
+
+	// 订单完成,移出租客
+	if err := chat.RemoveRenterFromListingConversation(tx, listing.ID, order.RenterID); err != nil {
+		// 移出失败不阻塞订单完成,仅记录日志
+		// TODO: 添加日志
+	}
+
 	return refund, nil
 }
 
diff --git a/backend/internal/modules/order/lifecycle.go b/backend/internal/modules/order/lifecycle.go
index bb31bd9..c4fa522 100644
--- a/backend/internal/modules/order/lifecycle.go
+++ b/backend/internal/modules/order/lifecycle.go
@@ -182,10 +182,18 @@ func (r *Repository) ConfirmPaidFromChannelTx(tx *gorm.DB, orderID uint64) (uint
 	order.HandoffStatus = handoffStatusPendingOwner
 	order.HandoffStartedAt = &now
 	markAssetsRented(listing, account)
-	conv, err := chat.EnsureOrderConversation(tx, *order)
-	if err != nil {
+
+	// 拉租客进发布群(替代原来的建订单群)
+	conversationID := uint64(0)
+	if err := chat.AddRenterToListingConversation(tx, listing.ID, order.RenterID, order.OrderNo); err != nil {
 		return 0, err
 	}
+	// 查询发布群ID用于返回
+	var listingConv model.ChatConversation
+	if err := tx.Where("listing_id = ?", listing.ID).First(&listingConv).Error; err == nil {
+		conversationID = listingConv.ID
+	}
+
 	if err := notification.Append(tx,
 		notification.Entry{
 			UserID:  order.OwnerID,
@@ -215,7 +223,7 @@ func (r *Repository) ConfirmPaidFromChannelTx(tx *gorm.DB, orderID uint64) (uint
 	if err := tx.Save(account).Error; err != nil {
 		return 0, err
 	}
-	return conv.ID, nil
+	return conversationID, nil
 }
 
 func (r *Repository) Cancel(ctx context.Context, userID uint64, orderID uint64) error {
@@ -271,6 +279,14 @@ func (r *Repository) Cancel(ctx context.Context, userID uint64, orderID uint64)
 		if err := closePendingOrderPayments(tx, order.ID, "order_cancel"); err != nil {
 			return err
 		}
+
+		// 订单取消,移出租客(仅付款后取消需要移出)
+		if beforeStatus == orderStatusPendingHandoff {
+			if err := chat.RemoveRenterFromListingConversation(tx, listing.ID, order.RenterID); err != nil {
+				// 移出失败不阻塞订单取消
+			}
+		}
+
 		if err := tx.Save(&order).Error; err != nil {
 			return err
 		}
diff --git a/backend/internal/router/router.go b/backend/internal/router/router.go
index d96cb9a..2cc7849 100644
--- a/backend/internal/router/router.go
+++ b/backend/internal/router/router.go
@@ -151,10 +151,7 @@ func New(cfg config.Config, deps Dependencies, logger *zap.Logger) *gin.Engine {
 	}
 	realnameService := realname.NewService(realnameRepo, newRealnameProvider(cfg, fieldEncryptor, logger), logger)
 	realnameHandler := realname.NewHandler(realnameService)
-	var listingRepo *listing.Repository
-	if deps.DB != nil {
-		listingRepo = listing.NewRepository(deps.DB)
-	}
+
 	var chatHub *chathub.Hub
 	if deps.DB != nil {
 		chatHub = chathub.NewHub(deps.DB)
@@ -163,6 +160,14 @@ func New(cfg config.Config, deps Dependencies, logger *zap.Logger) *gin.Engine {
 	if deps.DB != nil {
 		chatRepo = chat.NewRepository(deps.DB, chatHub)
 	}
+
+	// 创建 chat 适配器用于 listing
+	chatCreator := chat.NewListingChatCreatorAdapter()
+
+	var listingRepo *listing.Repository
+	if deps.DB != nil {
+		listingRepo = listing.NewRepository(deps.DB, chatCreator)
+	}
 	var paymentRepo *payment.Repository
 	var orderRepo *order.Repository
 	if deps.DB != nil {