diff --git a/src/register.ts b/src/register.ts
index d9d8dfb..610ae5c 100644
--- a/src/register.ts
+++ b/src/register.ts
@@ -1,7 +1,9 @@
 import cluster from 'cluster';
 import { debuglog } from 'util';
 import TsHelper, { TsHelperOption } from './core';
-import * as util from './utils';
+import {
+  convertString, checkMaybeIsJsProj, writeJsConfig, cleanJs,
+} from './utils';
 
 const debug = debuglog('egg-ts-helper#register');
 
@@ -23,17 +25,18 @@ export default class Register {
     // make sure ets only run once
     const pid = process.env.ETS_REGISTER_PID;
     if (pid) {
-      return debug('egg-ts-helper watcher has ran in %s', pid);
+      debug('egg-ts-helper watcher has ran in %s', pid);
+      return;
     }
 
-    const watch = util.convertString(process.env.ETS_WATCH, process.env.NODE_ENV !== 'test');
+    const watch = convertString(process.env.ETS_WATCH, process.env.NODE_ENV !== 'test');
     const clazz = this.tsHelperClazz;
     const cwd = options?.cwd || process.cwd();
     const instance = new clazz({ watch, ...options });
 
-    if (util.checkMaybeIsJsProj(cwd)) {
+    if (checkMaybeIsJsProj(cwd)) {
       // write jsconfig if the project is wrote by js
-      util.writeJsConfig(cwd);
+      writeJsConfig(cwd);
     } else {
       const tsNodeMode = process.env.EGG_TYPESCRIPT === 'true';
 
@@ -41,15 +44,19 @@ export default class Register {
       // clean local js file at first.
       // because egg-loader cannot load the same property name to egg.
       if (tsNodeMode && instance.config.autoRemoveJs) {
-        util.cleanJs(cwd);
+        cleanJs(cwd);
       }
     }
 
     // cache pid to env, prevent child process executing ets again
     process.env.ETS_REGISTER_PID = `${process.pid}`;
 
+    debug('start buidling');
     // exec building
     instance.build();
+    debug('end');
+    // reset ETS_REGISTER_PID
+    process.env.ETS_REGISTER_PID = '';
   }
 }