Method for protecting rolling reduction of roughing mill

The invention relates to a method for protecting rolling reduction of a roughing mill, which belongs to the technical field of advanced manufacturing and automation-automatic control, and comprises the following steps of: acquiring width and thickness values of a plate blank; on the basis of the obtained width value of the plate blank, the rolling reduction of the fixed-width press machine is judged, and when the rolling reduction of the fixed-width pressure meets the protection requirement, the plate blank is allowed to enter the fixed-width press machine; on the basis of the obtained width value of the plate blank, the rolling reduction of the vertical rolling mill is judged, and when the rolling reduction of the vertical rolling mill meets the protection requirement, the plate blank is allowed to enter the vertical rolling mill; on the basis of the obtained plate blank thickness value, the rolling reduction of the horizontal rolling mill is judged, and when the rolling reduction of the horizontal rolling m