In order to simulate dynamic buckling and lateral vibration of sucker rod string under axial load,a new hydraulic loading simulator based on program control was designed.Based on the hydraulic pressure closed-loop control mode,PLC was used to input set value to adjust the valve opening of the electrohydraulic pressure valve,to control the pressure of the system.And the real-time pressure of the hydraulic system was delivered to PLC by the pressure sensor，in order to control the continuous change of the system pressure and meet the design requirements.At the same time,the mathematical model of the hydraulic system was established by using Simulink module in MATLAB,the performance curve of the electrohydraulic pressure valve was simulated,and the stability and feasibility of the hydraulic closed-loop control system simulator was verified by parameter adjustment.