If you want to set the lock screen signature, you need to jailbreak the Apple phone to set it. The mobile phone before jailbreak does not have this function, but it can be set by a third-party theme software, which can change the theme and style of the desktop.

Jailbreak refers to a soft cracking operation on iOS by gaining full control and use right of Apple operating system iOS. The jailbroken iPhone has read and write access to the bottom of the system, allowing the iPhone to use the cracked AppStore software program for free.