The invention discloses an experimental device and method for promoting coal-bed methane extraction by utilizing ultrasonic waves and high-temperature CO2. The experimental device comprises a coal androck sample pressure bearing assembly, a confining pressure application assembly, an axial pressure application assembly, a simulated coal-bed methane filling assembly, an ultrasonic generation assembly, a high-temperature CO2 filling assembly, a temperature control assembly and a flow detection assembly. The experimental method comprises the following steps: mounting a coal and rock sample in the coal and rock sample pressure bearing assembly; performing simulated crustal stress loading on the coal and rock sample by the confining pressure application assembly; performing simulated coal-bedmethane adsorption on the coal and rock sample by the simulated coal-bed methane filling assembly; performing ultrasonic loading on the coal and rock sample through the ultrasonic generation assembly;performing displacement on the simulated coal-bed methane in the coal and rock sample through the high-temperature CO2 filling assembly; performing temperature monitoring on the high-temperature CO2filling assembly and the coal and rock sample by the temperature control assembly; and performing flow detection on the simulated coal-bed methane subjected to displacement in the coal and rock sampleby the flow detection assembly.