The geological conditions of the slope of Longtan Dam are complex, and the maximum slope height of the intake slope is 435m. In order to ensure the overall stability of the high slopes on the left and right banks and the long-term operation safety of the project, 1000kN, 2000kN and 3000kN prestressed anchor cables are used in the reinforcement and support of the left and right bank slopes of the Longtan Project to improve the overall stability of the slope. This article mainly introduces the design, construction, and tensioning program of prestressed anchor cables