1) In order to avoid prison break, you can back up your mobile phone first.
2) The 2)iphone itself can be backed up by cloud hosting or third-party software such as Tencent Mobile Manager.
3)iPhone can be restored to factory settings after jailbreaking. It is recommended to use itunes software to restore. The recovery operation is as follows:
Step 1: Log in to Apple official website, download itunes software, install it and open it.
Step 2: Connect the iphone to the computer with a data cable.
Step 3: In the summary interface, click "Restore iphone" and follow the instructions of itunes to restore the system version.
(Note: Please do not disconnect, cut off the power supply or use the equipment during the recovery process)