diff --git a/src/main/java/com/gaotao/modules/sys/controller/SysLoginController.java b/src/main/java/com/gaotao/modules/sys/controller/SysLoginController.java
index 5ac6966..af08550 100644
--- a/src/main/java/com/gaotao/modules/sys/controller/SysLoginController.java
+++ b/src/main/java/com/gaotao/modules/sys/controller/SysLoginController.java
@@ -1,4 +1,4 @@
- 
+
 
 package com.gaotao.modules.sys.controller;
 
@@ -32,7 +32,7 @@ import java.util.Map;
 /**
  * 登录相关
  *
- *  
+ *
  */
 @RestController
 public class SysLoginController extends AbstractController {
@@ -42,7 +42,7 @@ public class SysLoginController extends AbstractController {
 	private SysUserTokenService sysUserTokenService;
 	@Autowired
 	private SysCaptchaService sysCaptchaService;
-	
+
 	// 域控接口控制
 	@Value("${ldap-control.control-flag:false}")
 	private Boolean ldapFlag;
@@ -97,6 +97,7 @@ public class SysLoginController extends AbstractController {
 			if(user.getStatus() == 0){
 				return R.error(getLanguageMsg(SysMsgConstant.OBJECT_ID_200208));
 			}
+			// 域控账号允许多设备登录，不需要检查重复登录
 		}else {
 			user = sysUserService.queryByUserName(form.getUsername());
 			//账号不存在、密码错误
@@ -109,6 +110,9 @@ public class SysLoginController extends AbstractController {
 				return R.error(getLanguageMsg(SysMsgConstant.OBJECT_ID_200208));
 			}
 		}
+		if(sysUserTokenService.isUserLoggedIn(user.getUserId())){
+			return R.error("用户已经登录，请先退出后再登录");
+		}
 		session.setAttribute("user", user);
 
 		//生成token，并保存到数据库
@@ -126,5 +130,5 @@ public class SysLoginController extends AbstractController {
 		sysUserTokenService.logout(getUserId());
 		return R.ok(getLanguageMsg(SysMsgConstant.OBJECT_ID_200000));
 	}
-	
+
 }
diff --git a/src/main/java/com/gaotao/modules/sys/service/SysUserTokenService.java b/src/main/java/com/gaotao/modules/sys/service/SysUserTokenService.java
index 9fca107..3799cf8 100644
--- a/src/main/java/com/gaotao/modules/sys/service/SysUserTokenService.java
+++ b/src/main/java/com/gaotao/modules/sys/service/SysUserTokenService.java
@@ -25,4 +25,11 @@ public interface SysUserTokenService extends IService<SysUserTokenEntity> {
 	 */
 	void logout(long userId);
 
+	/**
+	 * 检查用户是否已登录（token是否有效）
+	 * @param userId  用户ID
+	 * @return true-已登录，false-未登录
+	 */
+	boolean isUserLoggedIn(long userId);
+
 }
diff --git a/src/main/java/com/gaotao/modules/sys/service/impl/SysUserTokenServiceImpl.java b/src/main/java/com/gaotao/modules/sys/service/impl/SysUserTokenServiceImpl.java
index 6392ee0..c9165c1 100644
--- a/src/main/java/com/gaotao/modules/sys/service/impl/SysUserTokenServiceImpl.java
+++ b/src/main/java/com/gaotao/modules/sys/service/impl/SysUserTokenServiceImpl.java
@@ -57,13 +57,24 @@ public class SysUserTokenServiceImpl extends ServiceImpl<SysUserTokenDao, SysUse
 
 	@Override
 	public void logout(long userId) {
-		//生成一个token
-		String token = TokenGenerator.generateValue();
+		//删除token记录
+		this.removeById(userId);
+	}
 
-		//修改token
-		SysUserTokenEntity tokenEntity = new SysUserTokenEntity();
-		tokenEntity.setUserId(userId);
-		tokenEntity.setToken(token);
-		this.updateById(tokenEntity);
+	@Override
+	public boolean isUserLoggedIn(long userId) {
+		//根据用户ID查询token
+		SysUserTokenEntity tokenEntity = this.getById(userId);
+		if(tokenEntity == null){
+			return false;
+		}
+		
+		//检查token是否过期
+		Date now = new Date();
+		if(tokenEntity.getExpireTime() == null || tokenEntity.getExpireTime().before(now)){
+			return false;
+		}
+		
+		return true;
 	}
 }