Abstract: For manufacturing of hot-rolled steel products,one of the key elements affecting the product quality is the furnace heating-caused scale on surface of the stock.A hi-pressure water descaler is jointly developed by Changsha Research Institute of Mining and the Hot-rolled Strip Steel Plant,Hangzhou I＆S Co.,Ltd.The said descaler is described here with details about its work principle,determination of the technical data,R＆D of the components as well as the effectiveness.