Abstract: Liquid carbon dioxide phase change gas explosion is a kind of point type gas gathering energy fracturing technology, and its three-dimensional effect on coal body cracking is an important criterion to explore the permeability improvement effect. Based on the self-designed and built physical experimental platform, the spatial-temporal evolution law of gas explosion pressure drop was obtained through experimental research. The spatial relationship between gas explosion pressure peak and blasting mouth distance was a quadratic parabola, and the fitting relationship was y=0.04x²-5.86x+227.6. The time relation between gas pressure rise time and blast hole distance is a power function form, and the fitting relation is y=8.78x^{0.143 7}. The numerical simulation results show that the plastic area of the gas energy gathering fracturing coal presents a similar ellipsoid development pattern with the axial direction of the blasting hole as the long axis. When the peak pressure of gas explosion is 160 MPa and 200 MPa, the maximum effective crack radius corresponding to the two working conditions is 0.50 m and 0.60 m respectively, and the maximum approximate crack radius increases by about 20%. The cracking volume was 0.50 m³ and 0.95 m³, respectively.