The invention relates to a numerical control reverse processing combined machine tool which is composed of a work fixture unit for fixing a part to be processed, a motor, an X axis direction guide way, a Y axis direction guide way, a Z axis direction guide way, a spindle box module for fixing tools, a sliding plate, a ram, an upright post and a base; the upright post and the base are provided with the X axis direction guide way, and the upright post is arranged on the base and can move along the X axis direction guide way; the upright post is provided with the Y axis direction guide way, and the sliding plate is arranged on the upright post and can move along the Y axis direction guide way; the sliding plate and the ram are provided with the Z axis direction guide way, and the ram is arranged on the sliding plate and can move along the Z axis direction guide way; the work fixture can be arranged on a revolving axle of a B axis; the upright post does horizontal linear movement oppositely to the base along the X axis direction; the sliding plate does vertical linear movement oppositely to the upright post along the Y axis direction; the sliding plate is arranged along the Z axis direction and internally provided with the ram, and square holes on the sliding plate and the ram longitudinally stretch back and forth to form the longitudinal and horizontal movement of the Z axis; the work fixture can be directly installed on the end face of the ram of the Z axis, or placed on the revolving axle of the B axis and then mounted on the end face of the ram, and the tool is installed on the spindle of a multi-spindle box.