Abstract: To ensure the safe, stable and economical operation of the hydropower station, the technical study and analysis are conducted according to the characteristics of the turbine generator unit of Shuangjiangkou Hydropower Station including the large generator capacity, high operating head, and the large quantity of sediments in the flow. Based on the analysis results, correspondent measures are worked out: to install cylindrical valve in the turbine. The necessity, feasibility and economic efficiency of the cylindrical valve are studied. The results show that the installation is technically feasible and economically efficient, which will provide reference for the installation of cylindrical valve in turbines of other hydropower stations in similar conditions.