In order to reduce the displacement output error of engine valve, the electrohydraulic actuator of engine valve was designed. The schematic diagram of the electrohydraulic actuator was created, and the piezoelectric brake and mechanical servo system were analyzed. The circuit control mathematical expression of the electrohydraulic actuator was given, and the flow equation of the hydraulic driving mechanism was established. The single PID control method was used and improved, and the series PI-PID-PI hybrid control method was designed. MATLAB software was used to simulate the output errors of valve movement displacement and piezoelectric displacement, and the results were compared and analyzed with those of single PID control method. The simulation results show that the output errors of valve movement displacement and piezoelectric displacement are less than 10% and the errors vary greatly by using the single PID control method; the output errors of valve movement displacement and piezoelectric displacement are less than 5% and the variation of errors is small by using the PI-PID-PI hybrid control method. With the method of series PI-PID-PI hybrid control, the response speed of the control system is faster, which can improve the control accuracy of the valve movement displacement and the valve movement characteristics, and the effect is better.