In order to strengthen the effect of gas drainage in coal seam, a numerical model of liquid CO2 gas explosion and fracturing in coal seam was constructed by using simulation software, and the optimization simulation of hole layout parameters was carried out by combining numerical simulation and industrial test, taking Huoerxinhe Coal Mine as the research object. The results show that the optimal arrangement spacing of the cracking holes in CO2 blasting is 4.5 m. After the optimization of the hole spacing, the gas extraction concentration of the borehole is increased by 73.7%, and the extraction flow is increased by about 5.1 times, which achieves a good gas extraction effect.