The Poyang Lake area,at the downstream of the Xinjiang,is featured by complex terrains and water system with multiple river branches.The selection of dam site has a large range of river sections,and the selection of the scheme of the hub dam site is complicated.Taking the Bazizui navigation and hydropower hub project in the Xinjiang as an example,based on meeting the requirements for navigation and the connectivity of the cascade in the upstream and downstream areas,we use a methodology for analyzing the pros and cons of various dam sites considering the functionality of each dam site,reasonable arrangement of river channels and banks,building layout,and minimizing reservoir inundation,and propose the idea of dam site selection.Then we carry out comprehensive comparison and selection of dam site selection from topography,geology,hub layout,project quantity,navigation conditions,channel connectivity,construction conditions,reservoir inundation,and overall project investment,and obtain the recommended dam site for the Bazizui navigation and hydropower hub project.Through a demonstration of the scheme,we clarify the strategy for dam site selection and hub layout,and successfully solve the problem of dam site selection in the complex water system and topographical conditions of the river mouth lake area.