Objective To analyze the abrasion resistance of polyurethane elastic coating and study its application in water conservancy engineering surface protection. Methods The cavitation erosion mechanism of the hydraulic turbine blade was analyzed, then a polyurethane elastomer wear-resistant layer was coated onto the blade of hydraulic turbine(0Cr13Ni5Mo) using the PU spraying technology and the performance of the coating was analyzed. Results When the functionality of polyurethane was 2. 4, the Polyurethane elastomers exhibited good mechanical performance, with the binding force between the coating and the turbine blades reaching up to 12. 6 MPa and the coating wear value remaining at the lower end of the range of 2 ~ 3 mg / 1000 r. Conclusion Elastic polyurethane coating can reduce erosion wear and cavitation damage caused by sediment flow on high-speed operating machine and equipment of water conservancy projects, and thus extends the service life of the pump impeller and turbine blade.