Abstract: Described in the paper is the working principle of the hi-pressure water surface descaling system for hot-rolled seamless steel tube self-designed and installed by Yantai Lubao Steel Tube Co., Ltd. The descaling system features fully utilizing the water, energy-saving and totally enclosed spray ring. Relevant site operation shows that thanks to the descaling system, tube surface quality is bettered, the material handling conditions improved and service span of the sizing mill roll groove increased.