Abstract: The realization of a high-intensity acoustic field is the key technology in thermoacoustic refrigerators. For this reason, this paper takes the half-wavelength standing wave type thermoacoustic refrigerator as the research object and analyzes the longitudinal forced vibration law of the gas column in the resonant cavity. On this basis, the idea of using the first-order piston modal vibration of the gas column instead of standing wave vibration in the thermoacoustic refrigerator is proposed to improve the amplitude of gas vibration in the resonant cavity and achieve large alternating gas flow. From the perspective of gas column piston modal vibration, including vibration patterns, pressure distribution, and temperature change laws of gas microgroups at the equilibrium position of vibration, heat transfer during the first-order piston modal vibration of the gas column is analyzed, thereby enhancing the reasonableness and feasibility of the refrigeration capacity. The superiority of applying first-order piston modal vibration of the gas column in thermoacoustic refrigerators is further illustrated by combining existing research results. The obtained results provide new research ideas and efforts to further enhance the sound field strength of thermoacoustic refrigerators.