How Huawei p9plus works? How does Tsinghua double clear mobile phones for p9plus?

When the mobile phone is turned off, press and hold the power button and the volume plus button at the same time, release the power button when the boot screen appears, and release the volume plus button after 3 seconds to enter the recovery mode. After entering, press the volume up/down key to select the corresponding function, and press the power key to confirm the selected function.

Select Erase Data/Restore Factory Settings to erase data and restore factory settings.

It is recommended to back up the important data in the mobile phone before the double clearing.