1. Open the cad software and select to open the locally prepared CAD file.

2. Enter the English PU in the command input field, and confirm to bring up the cleaning panel.

3. In the menu bar of the Cleanup panel, you can choose to clean up unnecessary content, such as layers.

4. Enter the "A" command to call out the confirmed cleaning items, and select the cleaning items as required.

5. Repeat the previous step. After cleaning, close the cad file, right-click the properties and check the file size.