Reservoir engineering construction often involves high slope excavation and support, facing many uncontrollable factors and great construction difficulties. Taking the slope protection construction of Liang Hekou Reservoir in Zizhong County as an example, combined with the hydro-geological conditions of the project area, this paper expounds the construction technologies of slope excavation, frame beam protection and sprayed mixed vegetation layer, and clarifies the relevant quality control technical parameters. Practice shows that according to the geological characteristics of the area where the project is located and the specific conditions of the slope, adopting appropriate slope excavation and support methods can greatly improve the support effect and ensure the quality and safety of slope protection construction.