Taking Huawei mate20 as an example, the dual system setting method is as follows:

1. First, find the setting button on the mobile phone desktop and enter the setting interface, as shown below.

2. Then on the Settings page, find the security and privacy options, and click, as shown in the figure below.

3. Next, slide to the bottom and select the privacy option, as shown in the figure below.

4. Then, after entering the privacy space interface, select the start button below, as shown in the figure below.

5. Next, set different access passwords between the privacy system and the main system, as shown in the figure below.

6. After the password is finally set, continue to select the fingerprint lock association option according to the system prompt, and then the two systems can complete the setting, as shown in the figure below.