diff --git a/packages/webpack-uni-mp-loader/lib/plugin/generate-component.js b/packages/webpack-uni-mp-loader/lib/plugin/generate-component.js
index 2be66a16fece6d1b19967f75cf2e928a767794f7..9f8a483ff95350e46efd5f444c44442f33de748f 100644
--- a/packages/webpack-uni-mp-loader/lib/plugin/generate-component.js
+++ b/packages/webpack-uni-mp-loader/lib/plugin/generate-component.js
@@ -128,7 +128,8 @@ module.exports = function generateComponent (compilation) {
       }
       if (name.endsWith('.wxss')) {
         // 移除部分含有错误引用的 wxss 文件
-        const origSource = assets[name].source().trim()
+        let origSource = assets[name].source()
+        origSource = origSource.trim ? origSource.trim() : ''
         const result = origSource.match(/^@import ["'](.+?)["']$/)
         if (result) {
           const wxssPath = path.join(path.dirname(name), result[1])