Abstract: Ultrasonic stimulation has the effect of increasing permeability and promoting sorption in coalbed methane development. This article conducted gas sorption experiments on coal with different water contents before and after ultrasonic excitation, and studied the influence of water content on the gas adsorption behavior under ultrasonic excitation. The results showed that the maximum adsorption capacity of raw coal, dry coal, and saturated coal for gas increased by 27.65%, 15.76%, and 47.30% respectively after ultrasound treatment, and the constant b values related to ad/de-sorption rates increased by 14.29%, 6.06%, and 23.53%, respectively, which is beneficial for promoting the desorption and diffusion process of coal gas. It indicates that ultrasonic excitation has a significant improvement effect on the ad/de-sorption capacity of coal gas. The higher the water content of the coal sample, the more significant the increase in adsorption capacity caused by ultrasound.