Aiming at 159 mm three roller hydraulic press control system of a seamless steel pipe plant in Inner Mongolia, the mathematical model of each part of the system was established. Ignoring some minor nonlinear factors, linear treatment for the system was done. The classical control theory was used to derive the transfer function, and the system time domain character and frequency domain character were analyzed.The conclusion was that the system response time was long and had steadystate error. Ziegler-Nichols tuning method was used to make PI, PID control. MATLAB software was used to make simulation and the ideal parameters were obtained, meeting the requirements of the rolling pressure control system.