Slab width measuring system for medium plate rolling line

The utility model discloses a plate blank width measuring system for a medium and heavy plate rolling line, which comprises a heating furnace, a discharge conveying roller way, a descaling device, a rough rolling conveying roller way, a steel rotating roller way and a rough rolling machine which are sequentially arranged, and a width measuring instrument used for automatically measuring the width of a plate blank is arranged above the rough rolling conveying roller way. A front manipulator is arranged on the outer side of the steel rotating roller way and can clamp a plate blank to achieve centering. According to the utility model, the width gauge is arranged above the rough rolling transportation roller way, so that the width of a plate blank can be automatically measured in the transportation process of the rough rolling transportation roller way, and a rolling schedule issuing position point of a secondary system is moved forwards to the width gauge, so that an operator has sufficient time to check through