1. If it is a form document, we can open it with WPS and click "Cloud Service" in the menu bar. The ribbon below has a "File Slimming" icon, click it.

2. If there is hidden data or format in the file, it will increase the size of the file. At this time, using file slimming can reduce the file size.

3. If it is a text document, it is usually because the image capacity is too large that the file is too large. After opening the document with WPS, select any picture and right-click to select "Format Object".

4. Then, select the Picture tab with the Compress button and click it.

5. At this point, we can select "All the pictures in the document", then change the resolution, and then click OK to compress all the pictures in the document and reduce the file size.