The utility model provides a nose steel sheet limit for height device, at the door frame formula limit for height frame that steel sheet rollgang top installation no. 1 comprises stand and crossbeam, the crossbeam welds in the upper end of two stands, and the stand lower extreme welds on the backplate of rollgang both sides. When supplied materials steel sheet head warpage exceeded the crossbeam of limit for height device, the post personnel can stop production immediately, transfinited the steel sheet handling with the nose and rolled off the production line to avoid the nose to transfinite the steel sheet and to the damage of rear portion shear line equipment, reduce the equipment accident, realize safe, high -efficient production, and prevent to improve the surface quality of steel sheet because the nose steel sheet hits and decreases the steel sheet surface that bilateral pinch roll caused and hang the wax phenomenon.