Abstract: In order to clarify the influence laws of high pressure gas blasting on the permeability of coal body, the experimental device of high pressure gas blasting in coal body was developed and the relevant experiment was carried out. The results show that the permeability of coal is more obvious when the hardness coefficient is between 0.5 and 1.5; the depth of blasting hole is about 1/3 of coal body, and the effect of high pressure gas blasting coal is better. With the increase of detonation pressure, the permeability of coal increases and basically changes linearly; as the confining pressure of coal increases, the increase of permeability of coal after high pressure gas blasting decreases correspondingly and presents a linear change; however, the pore pressure has little effect on the permeability improvement of high pressure gas blasting.