Abstract: In order to ensure the dam safety, prolong the life of metal structures, the effective anti- erosion measures must be taken.The reason for the defect that the metal structure surface got rusted, suffered friction and cavitation, was that the metal structure of Gezhouba discharge gate lied under water and in a damp environment for a long time, especially that arc gate and side track stayed under water and open- shut frequently, suffered the effect of high velocity flowand the extrusion of gate side watertight seal. The research on the newtechnology, newmaterials and newway to deal with the erosion was carried out and achieved many useful result. This article was a summary of the application result of anti- erosion technology, to set a good example and help to similar projects.