There are several ways to go, here I list two of them:
1. Standard Apple method. Launch iTunes on your computer. Connect your phone to your PC and wait for iTunes to recognize your device. An iTunes popup will display that offers to restore your iPhone using your most recent backup, then click "OK".
2. Third-party software method. If the method above still cannot work out. You can try to use some third-party softwares, like iPhone data recovery. It is compatible with your iPhone model and it can not only recover your iPhone data, but also help you get out of the recovery mode of your iPhone when it stuck in recovery mode. You can visit the following tutorial for more details:
[http://gg.gg/3od4k|iPhone Stuck in Recovery Mode]
Hope this helps!