Servo hydraulic cylinder is the core component of hydraulic rolling shear, which often requires horizontal articulated installation to output curve force.In order to avoid cylinder seuffing, leakage and insufficient output power caused by the gravity of cylinder itself, a novel support structure in which servo cylinder end hinge, a support cylinder was proposed along with its supporting control system.The control system needs to precisely control the pressure and displacement of the support of linder, so as to ensure the ful-ceroke and friction-less operation of the servo cylinder piston rod.As to this, the servo control system of a double closed-loop independent PID based on pressure-position was designed.Through the analysis and research on the coupling characteristics of pressure and position control system, the decoupling operation was carried out, the mathematical model of the system was deduced, and the stability of the system was analyzed by Lyapunov's Second Method.In order to verify the rationality of the pressure and position independent double loop PID control system, MATLAB/Simulink was used for simulation.Finally, it was proved that the control system is feasible and reliable in achieving the precise control of pressure and position of supporting cylinder.