In order to solve the problems of large flow rate and poor energy dissipation effect of Dahua Reservoir，the hydraulic physical model test was used to optimize the body of the stilling basin and the hydraulic parameters such as the flow state，velocity and energy dissipation rate of the stilling basin under the three optimization schemes.The research results show that the energy dissipation scheme of the two-stage stilling basin，in which the heights of the second stage stilling basin tail swill and tank are the same as that of the downstream riverbed，can effectively reduce the channel inlet flow rate by 68.62%and the mainstream flow velocity of the downstream river by 50.0%.The energy dissipation ratio of the dissipation basin is increased by 16.91%to 92.39%，which meets the requirements of downstream energy dissipation and flood prevention.The study can provide reference for similar engineering design.