Abstract: In order to improve the gas control effect in soft coal seam, based on the low temperature, low viscosity, high pressure phase transition expansion characteristics of liquid CO₂, liquid CO₂ fracturing permeability enhancement test for soft coal seam was carried out, the effect of gas extraction after fracturing test is investigated and studied. Experimental results showed that the fracturing influence region is formed by wall displacement zone, longitudinal fissure development zone and multi-fracture development zone around the fracturing hole, and the effective influence radius of injection is no less than 20 m; the extraction efficiency of the fracturing area is increased significantly, the mixed amount of extraction is increased, and the extraction concentration, the pure volume of extraction is nearly doubled; the period of the injection interval is 10 d, and shows a attenuation trend after 10 d; it has great advantage in safety and timeliness compared with the traditional way of increasing permeability.