Abstract: To study the influence laws of moisture on coal seam gas flow, taking raw coal samples in Zhaogu Mine of Jiaozuo Mining Area as the experimental object, we use thermofluid-solid coupled experiment to complete methane desorption experiment of loaded raw coal with the moisture content of 0.9%, 1.5%, 2.2%, 3.3% respectively under different gas pressure conditions. The experimental results show that the cumulative gas desorption capacity of the loaded raw coal in 100 min is linearly decreased with the increase of moisture when the moisture content is less than 3.3%; the desorption velocity index and the gas desorption velocity at 1 min is decreased when the moisture of the loaded raw coal is increased; the trend of attenuation of gas desorption velocity decreases, and gas desorption is more stable, and the possibility of coal and gas outburst at working face is reduced.