diff --git a/designer_base/src/com/fr/start/StartServer.java b/designer_base/src/com/fr/start/StartServer.java
index 9b674fd27f..af86fc4096 100644
--- a/designer_base/src/com/fr/start/StartServer.java
+++ b/designer_base/src/com/fr/start/StartServer.java
@@ -34,6 +34,7 @@ public class StartServer {
     // 原先的tomcatHost放在类TomcatHost里面，很不方便操作，而且因为存在多个进程的原因，
     // 原先的getInstance()方法无多大意义
     private static TomcatHost tomcatHost = null;
+    private static Object lock = new Object();
 
     static {
         GeneralContext.addEnvChangedListener(new EnvChangedListener() {
@@ -80,15 +81,17 @@ public class StartServer {
     }
 
     private static void initDemoServerAndBrowser() {
-        if (tomcatHost != null) {
-            if (!tomcatHost.isDemoAppLoaded()) {
-                tomcatHost.exit();
+        synchronized (lock) {
+            if (tomcatHost != null) {
+                if (!tomcatHost.isDemoAppLoaded()) {
+                    tomcatHost.exit();
+                    tomcatHost = new TomcatHost(DesignerEnvManager.getEnvManager().getJettyServerPort());
+                    tomcatHost.addAndStartInstallHomeWebApp();
+                }
+            } else {
                 tomcatHost = new TomcatHost(DesignerEnvManager.getEnvManager().getJettyServerPort());
                 tomcatHost.addAndStartInstallHomeWebApp();
             }
-        } else {
-            tomcatHost = new TomcatHost(DesignerEnvManager.getEnvManager().getJettyServerPort());
-            tomcatHost.addAndStartInstallHomeWebApp();
         }
         try {
             if (!tomcatHost.isStarted()) {
@@ -105,17 +108,19 @@ public class StartServer {
 
     public static void start() {
         try {
-            if (tomcatHost != null) {
-                if (NEED_LOAD_ENV) {
-                    tomcatHost.exit();
+            synchronized (lock) {
+                if (tomcatHost != null) {
+                    if (NEED_LOAD_ENV) {
+                        tomcatHost.exit();
+                        tomcatHost = new TomcatHost(DesignerEnvManager.getEnvManager().getJettyServerPort());
+                        tomcatHost.addAndStartLocalEnvHomeWebApp();
+
+                    }
+                } else {
                     tomcatHost = new TomcatHost(DesignerEnvManager.getEnvManager().getJettyServerPort());
                     tomcatHost.addAndStartLocalEnvHomeWebApp();
 
                 }
-            } else {
-                tomcatHost = new TomcatHost(DesignerEnvManager.getEnvManager().getJettyServerPort());
-                tomcatHost.addAndStartLocalEnvHomeWebApp();
-
             }
             if (!tomcatHost.isStarted()) {
                 tomcatHost.start();