Abstract: Supercritical CO₂ fracturing, as a new permeability enhancement technology, has been widely concerned by researchers because of its unique physical, chemical and mechanical properties of coal reservoir and its near zero damage to the reservoir.In this paper, the fracture initiation pressure and time, fracture propagation rule and permeability change of coal and rock mass under the action of different fracturing media are analyzed and compared.It is found that the fracture propagation form of hydraulic fracturing is single; the development degree of derivative fracture of liquid CO₂ fracturing is not high; the complexity of bedding fracture and derivative fracture formed by supercritical CO₂ fracturing is high.Especially, the initiation pressure of supercritical CO₂ fracturing coal is about 39.48% lower than that of hydraulic fracturing.The initiation time is more than 1.2 times that of hydraulic fracturing, and the change of permeability is about three times of that of hydraulic fracturing.Generally speaking, the transformation of the physical, chemical and mechanical properties of coal reservoirs by supercritical CO₂ provides new ideas and methods for the breakthrough in the theory and technology of fracture and permeability enhancement and coalbed methane production.