The structure of the machine is a three roll symmetrical type, with the upper roll performing vertical lifting and lowering movements at the symmetrical center of the two lower rolls. It is obtained by the hydraulic oil in the hydraulic cylinder acting on the piston rod, which is a hydraulic transmission; The two lower rollers rotate, and the output gear of the reducer meshes with the lower roller gear to provide torque for the rolled sheet; Multiple sets of rollers are installed at the lower part of the two rollers to improve their stiffness and allow for vertical adjustment; A rigid beam is installed at the upper part of the upper roller, and multiple sets of rollers are arranged between the beam and the upper roller to improve the stiffness of the upper roller; Suitable for rolling ultra wide arc-shaped parts.