1. Open PPT, click Insert, click Sound, click the sound in the file, insert the music in the file in the Insert Sound dialog box that pops up, and click OK. Select "Automatic" in the pop-up dialog box, and a small speaker will appear in PPT.

2. Select a small speaker, click "Options" under "Sound Tools", and check the option: loop until it stops. Checked: Hide when displayed. Play sound: Play across slides (set this item instead of "Stop playing" below).

3. Select the speaker again, click Animation, click Custom Animation, and the task pane will appear on the right. Right-click the drop-down arrow behind the music name box in the pane, and click the effect option in the drop-down options to set the effect: start (from the beginning) and stop playing (after the total number of slides). Timing: Repeat (until the end of the slide), and finally click OK. Music animation precedes other animations.

Especially emphasize two points: first, insert the music played from which page, and put the sound animation on top of other animations in the right pane; The second is to play several slides in succession, and fill in a few slides in the "Stop Playing" of the effect option.