The working face of the belt downhill in No. 23 mining area of Changcun Mine was a soft coal seam, in order to increase the crack distribution range of the top coal seam, eliminate the danger of gas outburst and avoid roofing on the mining surface, the CO2 pre-cracking anti-reflection technology was used to solve this problem. This paper used ANSYS_LS-DYNA3D software to analyze the influence characteristics of cracking technology on the face of the mining surface. It can be seen from the simulation results that the combination of the belt downhill was soft, with low permeability geological feature. The stress radius of the 15 blasting tubes was 32 m, which could meet the cracking requirements. The tracking of the measuring points was found that the stress near the cracked hole was concentrated, and then the attenuation began when the 15 blasting tubes was cracked,.