The system adopts the advanced electro-hydraulic servo control technology, provides energy by hydraulic pressure or pressure cylinders, and conducts servo control according to the pressure feedback signal, thickness measurement signal and the position feedback signal, with the help of tension, speed control, tilt roll, work roll positive and negative roll bending, and a variety of control methods to effectively achieved thickness accuracy and precision of the plate rolling strip. The system components and working principles are as follows: the thick control device is the double-loop control system, the inner loop is the position control loop (APC) or the pressure control loop (AFC), which is the core control link of the thickness control system. The actual output controls the actual pressure between the actual rolls or roll gaps. This step can work independently, to achieve constant roll gap or constant pressure rolling. The outerloop is the thickness control loop (AGC). Its output signal is used to correct the roll gap settings of the position loop or the pressure settings of the position loop. Through hydraulic servo control, the roll can be in quick action to achieve the purpose of the rapid elimination of thickness difference.