diff --git a/services/room-service/deploy/mysql/initdb/001_room_service.sql b/services/room-service/deploy/mysql/initdb/001_room_service.sql
index dd837fc1..494357e1 100644
--- a/services/room-service/deploy/mysql/initdb/001_room_service.sql
+++ b/services/room-service/deploy/mysql/initdb/001_room_service.sql
@@ -92,7 +92,7 @@ CREATE TABLE IF NOT EXISTS room_background_images (
   app_code VARCHAR(32) NOT NULL COMMENT '应用编码，用于多租户隔离',
   background_id BIGINT NOT NULL AUTO_INCREMENT COMMENT '背景图 ID',
   room_id VARCHAR(64) NOT NULL COMMENT '房间 ID',
-  image_url VARCHAR(1024) NOT NULL COMMENT '背景图 URL',
+  image_url VARCHAR(256) NOT NULL COMMENT '背景图 URL',
   created_by_user_id BIGINT NOT NULL COMMENT '保存背景图的用户 ID',
   created_at_ms BIGINT NOT NULL COMMENT '创建时间，UTC epoch ms',
   updated_at_ms BIGINT NOT NULL COMMENT '更新时间，UTC epoch ms',
diff --git a/services/room-service/internal/room/service/create_room.go b/services/room-service/internal/room/service/create_room.go
index 905bc370..b9b11cd7 100644
--- a/services/room-service/internal/room/service/create_room.go
+++ b/services/room-service/internal/room/service/create_room.go
@@ -34,7 +34,7 @@ const (
 	maxRoomNameRunes        = 128
 	maxRoomAvatarRunes      = 512
 	maxRoomDescriptionRunes = 512
-	maxRoomBackgroundRunes  = 1024
+	maxRoomBackgroundRunes  = 256
 )
 
 // roomProfileInput 是创建房间时需要落到 RoomExt 的展示资料集合。
diff --git a/services/room-service/internal/storage/mysql/repository.go b/services/room-service/internal/storage/mysql/repository.go
index 1800fb56..eda97585 100644
--- a/services/room-service/internal/storage/mysql/repository.go
+++ b/services/room-service/internal/storage/mysql/repository.go
@@ -151,7 +151,7 @@ func (r *Repository) Migrate(ctx context.Context) error {
 			app_code VARCHAR(32) NOT NULL,
 			background_id BIGINT NOT NULL AUTO_INCREMENT,
 			room_id VARCHAR(64) NOT NULL,
-			image_url VARCHAR(1024) NOT NULL,
+			image_url VARCHAR(256) NOT NULL,
 			created_by_user_id BIGINT NOT NULL,
 			created_at_ms BIGINT NOT NULL,
 			updated_at_ms BIGINT NOT NULL,