Using a high-response electro-hydraulic servo valve and making it work under the two extreme working conditions of valve port opening and closing,a valve-controlled hydraulic motor system was constructed to realize the control of the output speed and torque of the hydraulic motor,so as to explore the basic characteristics of the high-speed switch control method of the hydraulic motor.The design of the high-speed on/off valve-controlled hydraulic motor system and the construction of the AMESim simulation model were completed.The PWM signal was used to control the high-response electro-hydraulic servo valve to realize the high-speed switching control of the hydraulic motor,and the variation law of parameters such as rotation speed with duty cycle and frequency was obtained through simulation.An experimental prototype of a high-speed on/off valve-controlled hydraulic motor system based on a high-response electro-hydraulic servo valve was developed,and the experimental and simulation results were compared.The results show that the experimental and simulation results are consistent,and the speed of the hydraulic motor increases with the increase of duty cycle,and gradually decreases with the increase of external load.However,the conclusion that the increase of load will slightly accelerate the stability time of the hydraulic motor speed in the simulation results cannot be confirmed in the experiments.