Abstract: In order to improve the effect of permeability improvement in low permeability coal seam, a seam permeability improvement technology by high pressure air blasting is proposed, and its working principle and technological process are expounded. The high pressure air blasting is used to impact the coal body, which provides more flowing channels for gas, improved the coal permeability effective. The paper analyzed the factors influencing the crack effect of high pressure air blasting at the same time. Through numerical simulation, the influence factors of in-situ stress, high pressure air, coal hardness and gas pressure on the fracture of high pressure air blasting were studied. The results show that the high pressure air blasting can make the coal and rock medium produce crack effectively, the in-situ stress has an inhibitory action on the fracture propagation, and high pressure air, coal hardness and gas pressure has a positive impact on the fractures.