diff --git a/packages/uni-h5-vite/dist/plugins/css.js b/packages/uni-h5-vite/dist/plugins/css.js
index c8ded636c428436cf3eddc43adf2b6696537c17e..c47edf2f0becbb8ce8d0aae50cffec9cb435c9a1 100644
--- a/packages/uni-h5-vite/dist/plugins/css.js
+++ b/packages/uni-h5-vite/dist/plugins/css.js
@@ -31,8 +31,10 @@ function uniCssPlugin() {
             const entryName = entryChunk.name;
             const entryCssAsset = chunks.find(({ name }) => name === entryName + '.css');
             if (entryCssAsset) {
-                entryCssAsset.source +=
-                    '\n' + generateBuiltInCssCode([...uni_cli_shared_1.buildInCssSet]);
+                entryCssAsset.source =
+                    generateBuiltInCssCode([...uni_cli_shared_1.buildInCssSet]) +
+                        '\n' +
+                        entryCssAsset.source;
             }
         },
     };
diff --git a/packages/uni-h5-vite/src/plugins/css.ts b/packages/uni-h5-vite/src/plugins/css.ts
index 0e434d6934d11e8fad05e7fe8a041fcce5dd5e63..aea1c259337eaadf8db2c43be6a855ea69a82061 100644
--- a/packages/uni-h5-vite/src/plugins/css.ts
+++ b/packages/uni-h5-vite/src/plugins/css.ts
@@ -34,8 +34,10 @@ export function uniCssPlugin(): Plugin {
         ({ name }) => name === entryName + '.css'
       ) as OutputAsset
       if (entryCssAsset) {
-        entryCssAsset.source +=
-          '\n' + generateBuiltInCssCode([...buildInCssSet])
+        entryCssAsset.source =
+          generateBuiltInCssCode([...buildInCssSet]) +
+          '\n' +
+          entryCssAsset.source
       }
     },
   }