diff --git a/server/internal/logic/sys/im_group.go b/server/internal/logic/sys/im_group.go
index 9b2fd48..474796f 100644
--- a/server/internal/logic/sys/im_group.go
+++ b/server/internal/logic/sys/im_group.go
@@ -68,7 +68,7 @@ func (s *sSysImGroup) List(ctx context.Context, in *sysin.ImGroupListInp) (list
 }
 
 func (s *sSysImGroup) groupModel(ctx context.Context, db gdb.DB, tenantId int64) *gdb.Model {
-	return db.Model("im_topics t").Safe().Ctx(ctx).
+	return db.Model(tenantTablePrefix(tenantId)+"topics t").Safe().Ctx(ctx).
 		LeftJoin("im_group_settings gs", "gs.tenant_id = t.tenant_id AND gs.topic = t.name").
 		LeftJoin("im_users owner", "owner.tenant_id = t.tenant_id AND owner.id = COALESCE(gs.owner_user_id, t.owner)").
 		LeftJoin("im_user_profiles owner_profile", "owner_profile.tenant_id = t.tenant_id AND owner_profile.user_id = COALESCE(gs.owner_user_id, t.owner)").
@@ -140,7 +140,7 @@ func (s *sSysImGroup) View(ctx context.Context, in *sysin.ImGroupViewInp) (res *
 		return
 	}
 
-	err = db.Model("im_topics t").Safe().Ctx(ctx).
+	err = db.Model(tenantTablePrefix(tenant.Id)+"topics t").Safe().Ctx(ctx).
 		LeftJoin("im_group_settings gs", "gs.tenant_id = t.tenant_id AND gs.topic = t.name").
 		LeftJoin("im_users owner", "owner.tenant_id = t.tenant_id AND owner.id = COALESCE(gs.owner_user_id, t.owner)").
 		LeftJoin("im_user_profiles owner_profile", "owner_profile.tenant_id = t.tenant_id AND owner_profile.user_id = COALESCE(gs.owner_user_id, t.owner)").
@@ -210,15 +210,15 @@ func (s *sSysImGroup) MemberList(ctx context.Context, in *sysin.ImGroupMemberLis
 }
 
 func (s *sSysImGroup) hasGroupMemberTruth(ctx context.Context, db gdb.DB, tenantId int64, topic string) bool {
-	count, err := db.Model("im_group_members").Safe().Ctx(ctx).Where("tenant_id", tenantId).Where("topic", topic).Count()
+	count, err := db.Model(tenantTablePrefix(tenantId)+"group_members").Safe().Ctx(ctx).Where("tenant_id", tenantId).Where("topic", topic).Count()
 	return err == nil && count > 0
 }
 
 func (s *sSysImGroup) memberListFromBusiness(ctx context.Context, db gdb.DB, tenantId int64, in *sysin.ImGroupMemberListInp) (list []*sysin.ImGroupMemberListModel, totalCount int, err error) {
-	mod := db.Model("im_group_members gm").Safe().Ctx(ctx).
+	mod := db.Model(tenantTablePrefix(tenantId)+"group_members gm").Safe().Ctx(ctx).
 		LeftJoin("im_users u", "u.tenant_id = gm.tenant_id AND u.id = gm.user_id").
 		LeftJoin("im_user_profiles up", "up.tenant_id = gm.tenant_id AND up.user_id = gm.user_id").
-		LeftJoin("im_subscriptions s", "s.tenant_id = gm.tenant_id AND s.topic = gm.topic AND s.userid = gm.user_id").
+		LeftJoin(tenantTablePrefix(tenantId)+"subscriptions s", "s.tenant_id = gm.tenant_id AND s.topic = gm.topic AND s.userid = gm.user_id").
 		Fields(
 			"gm.user_id",
 			"up.nickname",
@@ -264,7 +264,7 @@ func (s *sSysImGroup) memberListFromBusiness(ctx context.Context, db gdb.DB, ten
 }
 
 func (s *sSysImGroup) memberListFromProjection(ctx context.Context, db gdb.DB, tenantId int64, in *sysin.ImGroupMemberListInp) (list []*sysin.ImGroupMemberListModel, totalCount int, err error) {
-	mod := db.Model("im_subscriptions s").Safe().Ctx(ctx).
+	mod := db.Model(tenantTablePrefix(tenantId)+"subscriptions s").Safe().Ctx(ctx).
 		LeftJoin("im_users u", "u.tenant_id = s.tenant_id AND u.id = s.userid").
 		LeftJoin("im_user_profiles up", "up.tenant_id = s.tenant_id AND up.user_id = s.userid").
 		Fields(
@@ -471,7 +471,7 @@ func (s *sSysImGroup) JoinRequestReject(ctx context.Context, in *sysin.ImGroupJo
 }
 
 func (s *sSysImGroup) resolveJoinRequest(ctx context.Context, in *sysin.ImGroupJoinRequestResolveInp, status string) (err error) {
-	db, _, err := resolveImTenantDB(ctx, in.TenantId)
+	db, tenant, err := resolveImTenantDB(ctx, in.TenantId)
 	if err != nil {
 		return err
 	}
@@ -497,10 +497,10 @@ func (s *sSysImGroup) resolveJoinRequest(ctx context.Context, in *sysin.ImGroupJ
 		}
 		applicantUserId := before["applicant_user_id"].Int64()
 		if status == consts.ImGroupRequestStatusAccepted {
-			if txErr = s.upsertGroupSubscription(ctx, tx, in.Topic, applicantUserId, imGroupModeMember, now); txErr != nil {
+			if txErr = s.upsertGroupSubscription(ctx, tx, tenant.Id, in.Topic, applicantUserId, imGroupModeMember, now); txErr != nil {
 				return txErr
 			}
-			if txErr = s.upsertGroupMember(ctx, tx, in.Topic, applicantUserId, consts.ImGroupRoleMember, "approval", actor, now); txErr != nil {
+			if txErr = s.upsertGroupMember(ctx, tx, tenant.Id, in.Topic, applicantUserId, consts.ImGroupRoleMember, "approval", actor, now); txErr != nil {
 				return txErr
 			}
 		}
@@ -514,7 +514,7 @@ func (s *sSysImGroup) resolveJoinRequest(ctx context.Context, in *sysin.ImGroupJ
 		if affected, _ := result.RowsAffected(); affected == 0 {
 			return gerror.New("入群申请已处理")
 		}
-		if txErr = s.recountGroupMembers(ctx, tx, in.Topic); txErr != nil {
+		if txErr = s.recountGroupMembers(ctx, tx, tenant.Id, in.Topic); txErr != nil {
 			return txErr
 		}
 		after, txErr := s.groupJoinRequestSnapshot(ctx, tx, in.Topic, in.RequestId)
@@ -644,8 +644,8 @@ func (s *sSysImGroup) groupJoinRequestSnapshot(ctx context.Context, tx gdb.TX, t
 		One()
 }
 
-func (s *sSysImGroup) groupMemberSnapshot(ctx context.Context, tx gdb.TX, topic string, userId int64) (res gdb.Record, err error) {
-	return tx.Model("im_group_members").Safe().Ctx(ctx).
+func (s *sSysImGroup) groupMemberSnapshot(ctx context.Context, tx gdb.TX, tenantId int64, topic string, userId int64) (res gdb.Record, err error) {
+	return tx.Model(tenantTablePrefix(tenantId)+"group_members").Safe().Ctx(ctx).
 		Where("topic", topic).
 		Where("user_id", userId).
 		One()
@@ -683,8 +683,8 @@ func (s *sSysImGroup) groupMuteSnapshot(ctx context.Context, tx gdb.TX, topic st
 		One()
 }
 
-func (s *sSysImGroup) ensureActiveGroupMember(ctx context.Context, tx gdb.TX, topic string, userId int64) error {
-	count, err := tx.Model("im_group_members").Safe().Ctx(ctx).
+func (s *sSysImGroup) ensureActiveGroupMember(ctx context.Context, tx gdb.TX, tenantId int64, topic string, userId int64) error {
+	count, err := tx.Model(tenantTablePrefix(tenantId)+"group_members").Safe().Ctx(ctx).
 		Where("topic", topic).
 		Where("user_id", userId).
 		Where("member_status", consts.ImGroupMemberStatusActive).
@@ -698,8 +698,8 @@ func (s *sSysImGroup) ensureActiveGroupMember(ctx context.Context, tx gdb.TX, to
 	return nil
 }
 
-func (s *sSysImGroup) ensureAdminLimit(ctx context.Context, tx gdb.TX, topic string, userId int64) error {
-	currentRole, err := tx.Model("im_group_members").Safe().Ctx(ctx).
+func (s *sSysImGroup) ensureAdminLimit(ctx context.Context, tx gdb.TX, tenantId int64, topic string, userId int64) error {
+	currentRole, err := tx.Model(tenantTablePrefix(tenantId)+"group_members").Safe().Ctx(ctx).
 		Where("topic", topic).
 		Where("user_id", userId).
 		Where("member_status", consts.ImGroupMemberStatusActive).
@@ -717,7 +717,7 @@ func (s *sSysImGroup) ensureAdminLimit(ctx context.Context, tx gdb.TX, topic str
 	if maxAdminCount.Int() <= 0 {
 		return nil
 	}
-	adminCount, err := tx.Model("im_group_members").Safe().Ctx(ctx).
+	adminCount, err := tx.Model(tenantTablePrefix(tenantId)+"group_members").Safe().Ctx(ctx).
 		Where("topic", topic).
 		Where("role", consts.ImGroupRoleAdmin).
 		Where("member_status", consts.ImGroupMemberStatusActive).
@@ -731,33 +731,38 @@ func (s *sSysImGroup) ensureAdminLimit(ctx context.Context, tx gdb.TX, topic str
 	return nil
 }
 
-func (s *sSysImGroup) upsertGroupSubscription(ctx context.Context, tx gdb.TX, topic string, userId int64, modeGiven string, now *gtime.Time) error {
-	_, err := tx.Exec(`INSERT INTO im_subscriptions(createdat,updatedat,deletedat,userid,topic,modewant,modegiven,private)
-		VALUES(?,?,NULL,?,?,?,?,CAST('{}' AS JSON))
+func (s *sSysImGroup) upsertGroupSubscription(ctx context.Context, tx gdb.TX, tenantId int64, topic string, userId int64, modeGiven string, now *gtime.Time) error {
+	table := tenantTablePrefix(tenantId) + "subscriptions"
+	_, err := tx.Exec(fmt.Sprintf(`INSERT INTO %s(tenant_id,createdat,updatedat,deletedat,userid,topic,modewant,modegiven,private)
+		VALUES(?,?,?,NULL,?,?,?,?,CAST('{}' AS JSON))
 		ON DUPLICATE KEY UPDATE createdat=VALUES(createdat),updatedat=VALUES(updatedat),deletedat=NULL,
-		modewant=VALUES(modewant),modegiven=VALUES(modegiven),delid=0,recvseqid=0,readseqid=0`,
-		now, now, userId, topic, imGroupModeMember, modeGiven)
+		modewant=VALUES(modewant),modegiven=VALUES(modegiven),delid=0,recvseqid=0,readseqid=0`, table),
+		tenantId, now, now, userId, topic, imGroupModeMember, modeGiven)
 	return err
 }
 
-func (s *sSysImGroup) upsertGroupMember(ctx context.Context, tx gdb.TX, topic string, userId int64, role string, joinSource string, joinedBy int64, now *gtime.Time) error {
-	_, err := tx.Exec(`INSERT INTO im_group_members(topic,user_id,role,member_status,join_source,joined_by,joined_at,version,created_at,updated_at)
-		VALUES(?,?,?,?,?,?,?,?,?,?)
+func (s *sSysImGroup) upsertGroupMember(ctx context.Context, tx gdb.TX, tenantId int64, topic string, userId int64, role string, joinSource string, joinedBy int64, now *gtime.Time) error {
+	table := tenantTablePrefix(tenantId) + "group_members"
+	_, err := tx.Exec(fmt.Sprintf(`INSERT INTO %s(tenant_id,topic,user_id,role,member_status,join_source,joined_by,joined_at,version,created_at,updated_at)
+		VALUES(?,?,?,?,?,?,?,?,?,?,?)
 		ON DUPLICATE KEY UPDATE role=VALUES(role),member_status=VALUES(member_status),join_source=VALUES(join_source),
-		joined_by=VALUES(joined_by),joined_at=VALUES(joined_at),left_at=NULL,removed_by=NULL,version=version+1,updated_at=VALUES(updated_at)`,
-		topic, userId, role, consts.ImGroupMemberStatusActive, joinSource, joinedBy, now, 1, now, now)
+		joined_by=VALUES(joined_by),joined_at=VALUES(joined_at),left_at=NULL,removed_by=NULL,version=version+1,updated_at=VALUES(updated_at)`, table),
+		tenantId, topic, userId, role, consts.ImGroupMemberStatusActive, joinSource, joinedBy, now, 1, now, now)
 	return err
 }
 
-func (s *sSysImGroup) recountGroupMembers(ctx context.Context, tx gdb.TX, topic string) error {
-	if _, err := tx.Exec(`UPDATE im_group_settings
-		SET member_count=(SELECT COUNT(*) FROM im_group_members WHERE topic=? AND member_status=?),updated_at=CURRENT_TIMESTAMP(3)
-		WHERE topic=?`, topic, consts.ImGroupMemberStatusActive, topic); err != nil {
+func (s *sSysImGroup) recountGroupMembers(ctx context.Context, tx gdb.TX, tenantId int64, topic string) error {
+	membersTable := tenantTablePrefix(tenantId) + "group_members"
+	subscriptionsTable := tenantTablePrefix(tenantId) + "subscriptions"
+	topicsTable := tenantTablePrefix(tenantId) + "topics"
+	if _, err := tx.Exec(fmt.Sprintf(`UPDATE im_group_settings
+		SET member_count=(SELECT COUNT(*) FROM %s WHERE tenant_id=? AND topic=? AND member_status=?),updated_at=CURRENT_TIMESTAMP(3)
+		WHERE tenant_id=? AND topic=?`, membersTable), tenantId, topic, consts.ImGroupMemberStatusActive, tenantId, topic); err != nil {
 		return err
 	}
-	_, err := tx.Exec(`UPDATE im_topics
-		SET subcnt=(SELECT COUNT(*) FROM im_subscriptions WHERE topic=? AND deletedat IS NULL),updatedat=CURRENT_TIMESTAMP(3)
-		WHERE name=?`, topic, topic)
+	_, err := tx.Exec(fmt.Sprintf(`UPDATE %s
+		SET subcnt=(SELECT COUNT(*) FROM %s WHERE tenant_id=? AND topic=? AND deletedat IS NULL),updatedat=CURRENT_TIMESTAMP(3)
+		WHERE tenant_id=? AND name=?`, topicsTable, subscriptionsTable), tenantId, topic, tenantId, topic)
 	return err
 }
 
diff --git a/server/internal/logic/sys/im_tenant_tables.go b/server/internal/logic/sys/im_tenant_tables.go
index a9b83df..9f34ee7 100644
--- a/server/internal/logic/sys/im_tenant_tables.go
+++ b/server/internal/logic/sys/im_tenant_tables.go
@@ -59,6 +59,10 @@ func provisionTenantMessageTables(ctx context.Context, tenantID int64) error {
 	baseTables := [][2]string{
 		{prefix + "friendships", "im_friendships"},
 		{prefix + "messages", "im_messages"},
+		{prefix + "topics", "im_topics"},
+		{prefix + "group_members", "im_group_members"},
+		{prefix + "subscriptions", "im_subscriptions"},
+		{prefix + "system_notifications", "im_system_notifications"},
 	}
 	for _, pair := range baseTables {
 		if _, err = db.Exec(ctx, fmt.Sprintf("CREATE TABLE IF NOT EXISTS `%s` LIKE `%s`", pair[0], pair[1])); err != nil {
diff --git a/server/storage/data/generate/im_additional_tenant_shards.sql b/server/storage/data/generate/im_additional_tenant_shards.sql
new file mode 100644
index 0000000..67fea71
--- /dev/null
+++ b/server/storage/data/generate/im_additional_tenant_shards.sql
@@ -0,0 +1,67 @@
+-- Existing-merchant migration for topics, group members, subscriptions and system notifications.
+-- Run against meeting_im. The script is idempotent and keeps the shared source tables intact.
+
+CREATE TABLE IF NOT EXISTS im_topics_bak_20260923_shard LIKE im_topics;
+INSERT IGNORE INTO im_topics_bak_20260923_shard SELECT * FROM im_topics;
+
+CREATE TABLE IF NOT EXISTS im_group_members_bak_20260923_shard LIKE im_group_members;
+INSERT IGNORE INTO im_group_members_bak_20260923_shard SELECT * FROM im_group_members;
+
+CREATE TABLE IF NOT EXISTS im_subscriptions_bak_20260923_shard LIKE im_subscriptions;
+INSERT IGNORE INTO im_subscriptions_bak_20260923_shard SELECT * FROM im_subscriptions;
+
+CREATE TABLE IF NOT EXISTS im_system_notifications_bak_20260923_shard LIKE im_system_notifications;
+INSERT IGNORE INTO im_system_notifications_bak_20260923_shard SELECT * FROM im_system_notifications;
+
+DROP PROCEDURE IF EXISTS migrate_additional_tenant_shards;
+DELIMITER $$
+CREATE PROCEDURE migrate_additional_tenant_shards()
+BEGIN
+    DECLARE done INT DEFAULT 0;
+    DECLARE current_tenant_id BIGINT;
+    DECLARE tenant_cursor CURSOR FOR SELECT id FROM hotgo.im_tenant ORDER BY id;
+    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
+
+    OPEN tenant_cursor;
+    tenant_loop: LOOP
+        FETCH tenant_cursor INTO current_tenant_id;
+        IF done = 1 THEN
+            LEAVE tenant_loop;
+        END IF;
+
+        SET @tenant_prefix = CONCAT('im_', LPAD(current_tenant_id, 3, '0'), '_');
+
+		SET @sql = CONCAT('CREATE TABLE IF NOT EXISTS `', @tenant_prefix, 'topics` LIKE `im_topics`');
+		PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+		SET @sql = CONCAT('ALTER TABLE `', @tenant_prefix, 'topics` MODIFY tenant_id BIGINT NOT NULL DEFAULT ', current_tenant_id, ' COMMENT ''商户ID''');
+		PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+		SET @sql = CONCAT('REPLACE INTO `', @tenant_prefix, 'topics` SELECT * FROM `im_topics` WHERE tenant_id=', current_tenant_id);
+		PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+        SET @sql = CONCAT('CREATE TABLE IF NOT EXISTS `', @tenant_prefix, 'group_members` LIKE `im_group_members`');
+        PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+        SET @sql = CONCAT('ALTER TABLE `', @tenant_prefix, 'group_members` MODIFY tenant_id BIGINT NOT NULL DEFAULT ', current_tenant_id, ' COMMENT ''商户ID''');
+        PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+        SET @sql = CONCAT('REPLACE INTO `', @tenant_prefix, 'group_members` SELECT * FROM `im_group_members` WHERE tenant_id=', current_tenant_id);
+        PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+        SET @sql = CONCAT('CREATE TABLE IF NOT EXISTS `', @tenant_prefix, 'subscriptions` LIKE `im_subscriptions`');
+        PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+        SET @sql = CONCAT('ALTER TABLE `', @tenant_prefix, 'subscriptions` MODIFY tenant_id BIGINT NOT NULL DEFAULT ', current_tenant_id, ' COMMENT ''商户ID''');
+        PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+        SET @sql = CONCAT('REPLACE INTO `', @tenant_prefix, 'subscriptions` SELECT * FROM `im_subscriptions` WHERE tenant_id=', current_tenant_id);
+        PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+        SET @sql = CONCAT('CREATE TABLE IF NOT EXISTS `', @tenant_prefix, 'system_notifications` LIKE `im_system_notifications`');
+        PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+        SET @sql = CONCAT('ALTER TABLE `', @tenant_prefix, 'system_notifications` MODIFY tenant_id BIGINT NOT NULL DEFAULT ', current_tenant_id, ' COMMENT ''商户ID''');
+        PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+        SET @sql = CONCAT('REPLACE INTO `', @tenant_prefix, 'system_notifications` SELECT * FROM `im_system_notifications` WHERE tenant_id=', current_tenant_id);
+        PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+    END LOOP;
+    CLOSE tenant_cursor;
+END$$
+DELIMITER ;
+
+CALL migrate_additional_tenant_shards();
+DROP PROCEDURE migrate_additional_tenant_shards;