1. First of all, I applied for opening the mobile phone shield online in the "My-Security and Settings-Security Tools-Manage Mobile Phone Shield" module of Bank of China Mobile Banking. The authentication methods when opening it are: face recognition+SMS, BOC E shield and SIM shield.

2. Secondly, after the authentication is passed, you need to set the mobile phone shield password with 6 digits.

3. Finally, enable the mobile phone transaction code function. This menu is enabled in "My-Security and Settings-Security Tools-Mobile Phone Single Transaction Code Switching" of mobile banking, and can be used at the same time after being enabled.