The level of optimization of concrete mix proportions directly affects the quality of concrete pouring and even the service life of the project. The article aims to study the secondary distribution of concrete proportion design of dam project of Lingxia Reservoir in Yudu County. The study develops the optimization sequence for the coarse aggregate gradation，optimal sand rate，admixture mixing，admixture mixing and water-cement ratio of the optimization of the concrete proportion of ideas. It also puts forward the optimal choice of the sand rate considering both compatibility and volume-weight，and calculates the linear regression equation of the optimal water-cement ratio for four strength classes of C15，C20，C25 and C30. The verified parameters and mixing amounts are in line with the actual project，which can be used as a reference for water conservancy project proportion design optimization research.