Aiming at currently steel enterprises special requirements of plate type and flatness of medium and heavy plate, and combining the advantages of electrichydraulic position control system and electrohydraulic force control system, a new based on the set value of pressure of complex control stragety was put forward, which can transform the position control to pressure control to achieve the purpose of straightening steel plate. By solving the system transfer function of asymmetrical valve to control asymmetrical hydraulic cylinder, both parallel and series compound control system were simulated and analyzed by using Matlab/Simulink software. Through the simulation, the stragety of compound control system was found of having faster response and smaller overshoot than that of the simply position or pressure control. The series compound control not only had the advantages of shorter rise time and faster response speed than that of parallel, but also could be able to achieve non overshoot and smooth transition at the switching from position to pressure. The research results show that series compound control system of electrohydraulic position and pressure is the development direction of hydraulic pressing down system of leveler in the future.