Security

As far as I know, there are two ways.
1. force factory reset(The data in the mobile phone will be deleted.)：
In the case that the mobile phone is not plugged into the USB data cable, press and hold the volume up button and the power button at the same time, release the power button when the boot screen appears, and release the volume up button after 3 seconds to enter the Recovery mode. After entering, choose to wipe data/factory reset and restart.
2. If you have turned on the mobile phone retrieve function，you can use the computer to log in to the official cloud service, the mobile phone retrieve function can unlock the mobile phone.

BYW，next time you have any question about mobile & home device issue, pls refer to:
Support: http://consumer.huawei.com/en/
There will be a more professional response.
You are also welcome to send an email to mobile@mail01.huawei.com or Hotline Service if you have any questions about Huawei Consumer products.
Thanks for your understanding.