1. Take Huawei P20 mobile phone as an example. First, open the WPS office software installed in the mobile phone.

2. Find the Word document whose name needs to be changed in the opened page, and click to enter the document editing interface.

3. Click on the position marked by the red circle in the lower left corner of the editing page.

4. Then click the "File" option in the opened page and select the "Save As" option.

5. You can save the open Word document, and you can modify the name of the document in this step.