diff --git a/internal/api/router.go b/internal/api/router.go
index 9f622be9e..ce16cd535 100644
--- a/internal/api/router.go
+++ b/internal/api/router.go
@@ -173,6 +173,8 @@ func newGinRouter(ctx context.Context, client discovery.SvcDiscoveryRegistry, co
 		userRouterGroup.POST("/set_group_invite_setting", u.SetGroupInviteSetting)
 		// 设置用户全局阅后即焚时长（秒），0 表示关闭
 		userRouterGroup.POST("/set_user_msg_burn_duration", u.SetUserMsgBurnDuration)
+		// 设置删除账号等待间隔（秒），0 表示使用系统默认（18个月）
+		userRouterGroup.POST("/set_delete_account_interval", u.SetDeleteAccountInterval)
 		// 批量查询阅后即焚、手机号可见性、音视频接收、全局/会话消息接收、群邀请等设置
 		userRouterGroup.POST("/get_user_privacy_settings", u.GetUserPrivacySettings)
 		// 根据手机号精确查找用户（phoneSearchVisibility=true 时遵守 phone_visibility 设置）
diff --git a/internal/api/user.go b/internal/api/user.go
index ad4e23fee..90f84fcbd 100644
--- a/internal/api/user.go
+++ b/internal/api/user.go
@@ -359,6 +359,10 @@ func (u *UserApi) SetUserMsgBurnDuration(c *gin.Context) {
 	a2r.Call(c, user.UserClient.SetUserMsgBurnDuration, u.Client)
 }
 
+func (u *UserApi) SetDeleteAccountInterval(c *gin.Context) {
+	a2r.Call(c, user.UserClient.SetDeleteAccountInterval, u.Client)
+}
+
 func (u *UserApi) GetUserPrivacySettings(c *gin.Context) {
 	a2r.Call(c, user.UserClient.GetUserPrivacySettings, u.Client)
 }
diff --git a/internal/rpc/user/user.go b/internal/rpc/user/user.go
index bb263e4db..abd64eaf0 100644
--- a/internal/rpc/user/user.go
+++ b/internal/rpc/user/user.go
@@ -455,6 +455,36 @@ func (s *userServer) SetUserMsgBurnDuration(ctx context.Context, req *pbuser.Set
 	return &pbuser.SetUserMsgBurnDurationResp{}, nil
 }
 
+// SetDeleteAccountInterval 设置用户删除账号等待间隔（秒）；
+// 0 表示重置为系统默认（18个月），要求 >= 0。只允许本人或管理员操作。
+func (s *userServer) SetDeleteAccountInterval(ctx context.Context, req *pbuser.SetDeleteAccountIntervalReq) (*pbuser.SetDeleteAccountIntervalResp, error) {
+	if req.UserID == "" {
+		return nil, errs.ErrArgs.WrapMsg("userID is required")
+	}
+	if req.DeleteAccountInterval < 0 {
+		return nil, errs.ErrArgs.WrapMsg("deleteAccountInterval must be >= 0 (seconds)")
+	}
+	if err := authverify.CheckAccessV3(ctx, req.UserID, s.config.Share.IMAdminUserID); err != nil {
+		log.ZWarn(ctx, "SetDeleteAccountInterval: access denied", err,
+			"opUserID", mcontext.GetOpUserID(ctx), "targetUserID", req.UserID)
+		return nil, err
+	}
+	if _, err := s.db.FindWithError(ctx, []string{req.UserID}); err != nil {
+		log.ZError(ctx, "SetDeleteAccountInterval: user not found or db error", err,
+			"opUserID", mcontext.GetOpUserID(ctx), "targetUserID", req.UserID)
+		return nil, err
+	}
+	if err := s.db.UpdateByMap(ctx, req.UserID, map[string]any{
+		"delete_account_interval": req.DeleteAccountInterval,
+	}); err != nil {
+		log.ZError(ctx, "SetDeleteAccountInterval: UpdateByMap failed", err,
+			"opUserID", mcontext.GetOpUserID(ctx), "targetUserID", req.UserID,
+			"deleteAccountInterval", req.DeleteAccountInterval)
+		return nil, err
+	}
+	return &pbuser.SetDeleteAccountIntervalResp{}, nil
+}
+
 // GetUserPrivacySettings 返回当前登录用户（ctx opUserID）的隐私与接收相关设置。
 func (s *userServer) GetUserPrivacySettings(ctx context.Context, req *pbuser.GetUserPrivacySettingsReq) (*pbuser.GetUserPrivacySettingsResp, error) {
 	userID := mcontext.GetOpUserID(ctx)
@@ -468,13 +498,15 @@ func (s *userServer) GetUserPrivacySettings(ctx context.Context, req *pbuser.Get
 		return nil, err
 	}
 	u := users[0]
+
 	return &pbuser.GetUserPrivacySettingsResp{
-		MsgBurnDuration:    u.MsgBurnDuration,
-		PhoneVisibility:    u.PhoneVisibility,
-		CallAcceptSetting:  u.CallAcceptSetting,
-		GlobalRecvMsgOpt:   u.GlobalRecvMsgOpt,
-		MsgReceiveSetting:  u.MsgReceiveSetting,
-		GroupInviteSetting: u.GroupInviteSetting,
+		MsgBurnDuration:       u.MsgBurnDuration,
+		PhoneVisibility:       u.PhoneVisibility,
+		CallAcceptSetting:     u.CallAcceptSetting,
+		GlobalRecvMsgOpt:      u.GlobalRecvMsgOpt,
+		MsgReceiveSetting:     u.MsgReceiveSetting,
+		GroupInviteSetting:    u.GroupInviteSetting,
+		DeleteAccountInterval: u.DeleteAccountInterval,
 	}, nil
 }
 
diff --git a/pkg/common/storage/database/mgo/user.go b/pkg/common/storage/database/mgo/user.go
index 9ba0a0514..25044cb1d 100644
--- a/pkg/common/storage/database/mgo/user.go
+++ b/pkg/common/storage/database/mgo/user.go
@@ -57,6 +57,11 @@ type UserMgo struct {
 }
 
 func (u *UserMgo) Create(ctx context.Context, users []*model.User) error {
+	for _, user := range users {
+		if user.DeleteAccountInterval == 0 {
+			user.DeleteAccountInterval = model.DefaultDeleteAccountIntervalSec
+		}
+	}
 	return mongoutil.InsertMany(ctx, u.coll, users)
 }
 
diff --git a/pkg/common/storage/model/user.go b/pkg/common/storage/model/user.go
index 503ccfb57..1eac5c35a 100644
--- a/pkg/common/storage/model/user.go
+++ b/pkg/common/storage/model/user.go
@@ -58,6 +58,10 @@ const (
 	UserStatusBlacklist int32 = 2
 )
 
+// DefaultDeleteAccountIntervalSec 删除账号等待间隔的系统默认值（18 个月，按 30 天/月折算）。
+// 注册时写入 MongoDB 的初始值；用户未显式修改时即为此值。
+const DefaultDeleteAccountIntervalSec int32 = 18 * 30 * 24 * 3600
+
 type User struct {
 	UserID             string    `bson:"user_id"`
 	Nickname           string    `bson:"nickname"`
@@ -81,6 +85,8 @@ type User struct {
 	Status int32 `bson:"status"`
 	// MsgBurnDuration 用户全局消息阅后即焚时长（秒）；0 表示关闭
 	MsgBurnDuration int32 `bson:"msg_burn_duration"`
+	// DeleteAccountInterval 删除账号间隔（秒）；0 表示关闭
+	DeleteAccountInterval int32 `bson:"delete_account_interval"`
 }
 
 func (u *User) GetNickname() string {
diff --git a/protocol b/protocol
index f7bfce630..24c722593 160000
--- a/protocol
+++ b/protocol
@@ -1 +1 @@
-Subproject commit f7bfce630638a3dc3fd776842d1c3e8078559269
+Subproject commit 24c72259373e9080ab005bb10385524753d4dfc3