To provide a safety operation method for a plate processing machine with numerical control device, capable of performing safety operation by a double operation monitoring system, such that axial movement can be stopped simultaneously with alarm display of overhang of a work from a work table by automatic check from a processing program, while processing can be restarted after restart is instructed, and further the axial movement can be stopped, even in origin restoration after completion of the processing, simultaneously with alarm display of the overhand by automatic check.

The safety operation method for the plate processing machine with numerical control device includes: arithmetically determining whether a work is overhung from the work table of the plate processing machine from size data of the work obtained from the processing program and coordinate data obtained from a processing instruction value; stopping, when overhang is determined, the axial movement of a plate positioning device simultaneously with display of alarm on a display device; and restarting the processing when restart is instructed.