Abstract: The throttle valve is a very important control element in the refrigeration cycle. Relying on the movement of the valve core and valve body to change the beam section to achieve the purpose of the throttle. During the operation process, the stop throttle valve is prone to cavitation in the valve, causing the vibration of the valve body and the valve core to produce noise and seriously affecting the working efficiency and service life of the valve. Therefore, it is of great significance to study the cavitation characteristics in the valve. This paper studies the influence of the valve core position and the inlet pressure on the inlet flow velocity, and calculates the pressure distribution, cavitation distribution and flow velocity distribution. The results show that as the distance between the valve seat and the valve stem increases, the cavitation decreases, as the inlet pressure and the inlet velocity increase, the cavitation increases.