High-frequency S-wave seismogram envelopes of microearthquakes are broadened with increasing travel distance, which is called S-wave envelope broadening. The results show that the phenomenon of S-wave envelope broadening in Changbaishan Tianchi volcano is obvious, and the peak delay time of S-wave has a positive correlation with hypocenter distance and frequency of S-wave. The relationships between the peak delay time of S-wave and the hypocenter distance for different frequency bands were got by statistics method. The results are beneficial to the understanding of the S-wave envelope broadening phenomena and the quantitative research on the inhomogeneities of the crust medium in the Changbaishan Tianchi volcano region.