diff --git a/packages/webpack-uni-mp-loader/lib/plugin/generate-json.js b/packages/webpack-uni-mp-loader/lib/plugin/generate-json.js
index df912a46bf14d08f599fbba61c7100cd6d5b7bfc..f9f06cb684fe245b826f76f2e08023fe41781cbf 100644
--- a/packages/webpack-uni-mp-loader/lib/plugin/generate-json.js
+++ b/packages/webpack-uni-mp-loader/lib/plugin/generate-json.js
@@ -51,7 +51,7 @@ function analyzeUsingComponents () {
         return false
       }
       pkgs.add(pkgRoot)
-      if (pkgs.length > 1) { // 被多个分包引用
+      if (pkgs.size > 1) { // 被多个分包引用
         return false
       }
     }
@@ -223,4 +223,4 @@ module.exports = function generateJson (compilation) {
       require('@dcloudio/uni-cli-shared/lib/cache').store()
     }, 50)
   }
-}
+}