The utility model relates to a heavy and medium steel plate face water cutting device which comprises a rolling mill guard, a water cutting header and a high-pressure nozzle are installed on the rolling mill guard through a pipe clamp and an installation support, and the water cutting header is connected with a water inlet pipe through a second connecting hose and a connecting steel pipe. High-pressure water is adopted to be sprayed onto the surface of a steel plate through the water cutting header and the high-pressure nozzle which are installed on the rolling mill guard to remove waterlogging on the surface of the steel plate generated due to descaling on a machine, steel plate surface quality problems and thickness gauge measurement errors caused by the waterlogging on the surface of the steel plate are avoided, quality of products is guaranteed, production efficiency is improved, and production cost is reduced.