At present, the short pipe throttle valve has replaced the application of capillary in air conditioning, while there is less research on the cavitation flow and noise of short pipe throttle valve in China. The research of short pipe throttle valve was focused on.Taking R134A refrigerant as refrigerant, through the numerical analysis of the refrigeration process of air conditioning under different flow rates, the distributions of cavitation, noise, pressure field and velocity field were obtained.The results show that when the pressure difference between the inlet and outlet of the valve remains unchanged, the larger the inlet flow is, the more serious the cavitation is; the noise first increases, then decreases and then increases with the increase of flow; the location of the maximum noise gradually moves downstream with the increase of flow; shear force and cavitation collapse are the factors affecting noise, but in contrast, cavitation collapse is the dominant factor affecting noise.