Metal cutting machine

The invention discloses a metal cutting machine. The metal cutting machine comprises a workbench, a controller, a mounting seat and a cutting knife, the cutting knife and the mounting seat are arranged on the same side of the workbench, a telescopic device is arranged between the mounting seat and the cutting knife, the telescopic end of the telescopic device is detachably and fixedly connected with the cutting knife, and the telescopic device is connected and hinged to the mounting seat. A rotating surface formed by the telescopic device in the rotating direction of the mounting seat is perpendicular to the mounting seat; and the controller is electrically connected with the telescopic device and used for controlling the telescopic device to drive the cutting knife so that the cutting knife can move in the telescopic direction of the telescopic end to cut a metal piece. According to the technical scheme, the telescopic device is connected with the mounting seat and the cutting knife, so that the cutting rang