This article discussed thermoacoustic refrigeration with method of numerical simulation. Provided theory model of numerical simulation firstly, and simulated a thermoacoustic cooler model. Researches focus on temporal and spatial variation of parameters including temperature, velocity, pressure, density and turbulent intensity. Treated the heat exchangers and resonator as porous media, with 15atm pressure and 20Hz frequency, achieved the lowest temperature is 243K. Discussed the mechanism of these results at last, deem that the gas, at the impact of pressure wave, oscillated back and forth in pulse tube, urge the heat in right space transmitted outside via exchangers and resonator. These conclusions will take guiding function for the development of thermoacoustic cooler.