Due to the high temperature oxidation and mechanical wear during the rolling process of the steel sheet, the roll surface will cause geometrical damage to the roll surface, and the roll surface needs to be periodically ground and repaired. And in order to meet the process requirements for shape control, the roll surface bus bar needs to be processed into various special high-power curves required according to different process requirements. At the same time, the roll surface buses of the work roll and the support roll must be coupled and matched with each other according to certain requirements, so the processing is difficult. The product is a metal cutting machine, consisting of a bed, a headstock, a tailstock, a bracket, a crossbar, a grinding head, a measuring frame, and an electric numerical control system. It is divided into a bearing system, a drive system, a grinding system, a measurement system and a control Five subsystems of the system. The workpiece is supported by the headstock, tailstock and bracket, and is driven to rotate by the headstock. The numerical control system controls the machine tool to perform multi-axis compound movement according to the mathematical model of the roller surface generatrix, and realizes the grinding of the metal on the roller surface by the grinding wheel during the movement. The online measurement system feeds back the measurement data to the grinder control system in real time, and the control system controls the machine tool in a closed loop to complete the precise machining of the workpiece.