diff --git a/package.json b/package.json
index 60db77d..74f8286 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
     "name": "shrimp-server",
-    "version": "0.7.10",
+    "version": "0.7.11",
     "description": "Shrimp 框架后端 — 声明式字段驱动的 Node.js 管理后台框架(Express + Mongoose + JWT)",
     "main": "dist/main/index.js",
     "types": "dist/main/index.d.ts",
diff --git a/src/forMongo/MongoShrimpCrud.ts b/src/forMongo/MongoShrimpCrud.ts
index cc7ff29..b69d044 100644
--- a/src/forMongo/MongoShrimpCrud.ts
+++ b/src/forMongo/MongoShrimpCrud.ts
@@ -79,9 +79,10 @@ export class MongoShrimpCrud<T> implements ShrimpCrud<T> {
             const allRefIds = new Set<string>()
             for (const item of items) {
                 const val = (item as any)[pop.key]
+                // 跳过空串：可选 Relation 常存 ""，混进 { _id: { $in } } 会让 Mongoose 转 ObjectId 抛 CastError、整页 500。
                 if (Array.isArray(val)) {
-                    val.forEach((id: any) => { if (id != null) allRefIds.add(String(id)) })
-                } else if (val != null) {
+                    val.forEach((id: any) => { if (id != null && id !== "") allRefIds.add(String(id)) })
+                } else if (val != null && val !== "") {
                     allRefIds.add(String(val))
                 }
             }