Abstract: To rationally and accurately predict the installed capacity of the river ecological power station, four target layers, namely power generation benefit, unit utilization efficiency, waste water and investment were selected and an analytical hierarchy model of ecological power station installation scheme was developed.This model was applied in the Yuwangxi Hydropower Station on Tangbai River Basin.It is showed that the model can not only optimize the installation scheme based on the importance of targeted objectives, but also improve the efficiency of the ecological flow utilization by identifying the functional requirements of power station during installation.The proposed method can better determine the ecological flow installation scheme, which provides essential theoretical guidance for the decision-making of the installed capacity in the green transformation of hydropower stations.