In order to make electrohydraulic load simulator can realize complex loading force, implementing requisite loading by programming with instruction in Programmable Logic Controller (PLC), and acceding the PID calculation to improve the quality of controlled volume, an effective method to realize complex loading force on electrohydraulic load simulator was provided. In the process of realizing complex loading force, making use of timer to delay output control signal of position system, the problem of force lagging in force system is solved.