1. 确认网络密码是否正确

2. 确认手机和路由器之间的距离，保持手机和路由器之间的距离在合理范围内

3. 尝试重启手机和路由器

4. 清除网络设置缓存，具体步骤如下：

   a. 进入“设置”-“应用程序管理器”

   b. 找到“所有应用程序”-“系统应用程序”

   c. 找到“网络设置”-“清除数据”

5. 进入手机的“开发人员选项”，将“Wi-Fi保持活动”选项关闭

6. 确认网络是否有MAC地址过滤，将手机的MAC地址添加到白名单中

7. 使用以下代码示例尝试解决问题：

   WifiManager wifiManager = (WifiManager)getSystemService(Context.WIFI_SERVICE);

   WifiConfiguration wifiConfiguration = new WifiConfiguration();

   wifiConfiguration.SSID = ""SSID"";

   wifiConfiguration.preSharedKey = ""password"";

   wifiConfiguration.hiddenSSID = true;

   wifiConfiguration.status = WifiConfiguration.Status.ENABLED;

   wifiConfiguration.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);

   wifiConfiguration.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);

   wifiConfiguration.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);

   wifiConfiguration.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);

   wifiConfiguration.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);

   wifiConfiguration.allowedProtocols.set(WifiConfiguration.Protocol.RSN);

   int networkId = wifiManager.addNetwork(wifiConfiguration);

   wifiManager.disconnect();

   wifiManager.enableNetwork(networkId, true);

   wifiManager.reconnect();

以上方法如果仍然无法解决问题，可以尝试重置手机到出厂设置。