The invention relates to a high-temperature high-pressure physical model using X-CT to scan a fracture cavity. The physical model is composed of an X-CT scanner, a fracture cavity simulation container3, a pressure gauge 5, a back pressure valve 6, a gas-liquid separator 8, a gas meter 9, a constant-flux pump 10, an intermediate container set I 11 and an intermediate container set II 12, wherein the fracture cavity simulation container 3 is fixed on a scanning frame, and an X-ray generation system scans the fracture cavity simulation container, and displays the scanning result on a display screen of a console; a fracture cavity simulation rock sample 15 is placed in a kettle body of the fracture cavity simulation container, a built-in interlayer 14 is arranged between the kettle body and the rock sample, and a heating layer 17 is arranged outside the kettle body in a covering mode; an injection port and an extraction port are formed in the two sides of the fracture cavity simulation container correspondingly, the injection port is connected with the intermediate container set I and the constant-flux pump 10, and the extraction port is sequentially connected with the pressure gauge5, the back pressure valve 6, the gas-liquid separator 8 and the gas meter 9; and a gas injection port is formed in the top end of the fracture cavity simulation container, and a stratum water injection port is formed in the bottom end of the fracture cavity simulation container. The model has the advantages that the occupied space is small, the operation is flexible, and the great guiding significance is provided for actual development of the fracture cavity oil reservoir.