Abstract: This paper designs atheory of digital watermark embedding on basis of frequency masking effects to solve the application of digital watermark embedding in audio files.It also details the process for watermark embedding and extracting by using the masking effects, and provides the key calculation functions during the two processes.After testing and analyzing the designed watermark algorithms, it can be learned that the embedding algorithm in this study has a better invisibility and robustness which can resist the common attack method of digital watermarks.However, the sampling results are not desired when it meets the cropping attack on the anti-sampling points.