In this study, PP masterbatch was mixed with PLA particles in different proportions, and melt-blown nonwoven fabric was made by melt-blown method. When the PLA content is 1%, 3%, because the PLA content is not high, the effect on the sound absorption effect before and after dissolution is not obvious. When the content reaches 5%, although the sound absorption coefficient increases by 0.16 after dissolution, the PLA content is already the highest content added at 5%, so the sound absorption performance that can be improved by the concave reflection theory in this experiment is limited. When the PLA content is 1%, the sound absorption coefficient reaches 0.86 at a frequency of 6300 Hz, and the sound absorption effect is the best. When the basis weight is increased to 300g, the PP/1% PLA and PP/3% PLA meltblown non-woven fabrics are in the middle, and the sound absorption coefficient at high frequencies rises by an average of 0.2, the sound absorption effect is in the middle, and the middle school has a significant increase.