1, open the mobile phone, we find the little red book APP on the mobile phone, click this software to enter the main interface.

2. After entering the main interface of the software, we find the "I" option in the lower right corner of the interface, and click this option to enter my page.

3. In my page, we found that there is a "Click here to change the background picture" button at the top of the page. Click this button to enter the next step.

4. You can enter the file management page, where we can find the picture that needs to be set as the background picture and select it.