Tongkou power station is an all-round hydro project,where the mixed exploitation mode is adopted with mainly for power generation.Integrated with the model test result,the duct discharge capacity and flow coefficient in various discharge hole are discussed,the influence of duct shape on inlet pressure,energy dissipation and tail water is analyzed,the improvement measures on conveyer way pressure and energy dissipation are put forward too.The achievements of this study have been adopted by the designers.