if you don’t know what is root and how it works, then please don’t try it, i would never suggest it until unless you really need this. Basically rooting provides you access to system partition of your smartphone, where you can modify certain things in system.
in this post i will guide you how you can root Huawei Mate7 After Marshmallow firmware installed.

Process:

1. Your phone bootloader must be unlocked.  (How to unlock bootloader?)
2. Turn on USB debugging , and install TWRP recovery using this too: recovery mate7 mopbox v2.1.exe  (Tutorial: How to download from despoitfiles)
3. Once recovery tool downloaded, switch off your phone and hold volume down button, then connect with PC
4. your phone should boot into fastboot mode as shown in picture below

5. Now open Recovery tool and select number “4” to install TWRP recovery for marshmallow, if successfully installed you will see following screen

6. Now restart your phone, and download : SuperSU_v2.64_Pro.zip
7. Copy SuperSU file inside your phone memory
8. Restart phone in twrp recovery mode, (switch off phone then hold Volume up + power button)
9.Once you enter twrp recovery swipe to allow modification
10. On next screen you should select ” Install”

How to root huawei mate7 in marshmallow

11. on next screen select the superSU zip file that you copied in memory of your phone.

12. On next screen it will show you several option, don’t select anything, just slide the arrow at bottom to right side.

13. installation will take few seconds, after that, reboot your phone. if you see superSU icon , that means you have successfully rooted your phone.

Kindly watch following video tutorial for more details