It can be set through the following methods:

EMUI3.0 and EMUI3.1 versions: Click "Settings > Application Management > Default Application Settings > Desktop" and select the installed third-party desktop as Default desktop.

EMUI4.0 and EMUI4.1 versions: Click "Settings > Application Management > Advanced > Default Application Settings > Desktop" to select the installed third-party desktop as the default desktop.

EMUI5.X: System Settings>Application Management>Settings>Default Application Settings>Music Desktop, select the installed third-party desktop as the default desktop.

EMUI8.0 (taking Mate10 as an example): System settings > Applications and notifications > Default application settings > Desktop, select the installed third-party desktop as the default desktop.

EMUI 8.1 and above: Huawei has received feedback from some users that they encountered problems such as stability and push ads when using third-party desktops. In order to enable you to use your phone more smoothly and with confidence, we will protect you. To protect your privacy and legitimate rights and interests, to avoid the above problems, it is prohibited to set the third-party desktop as the default desktop. Thank you for your understanding and support!