The project section of Pinglu Canal Youth Hub is located in a curved channel，with numerous bridges and dense buildings at the dam site.The reservoir area of Youth Hub is the drinking water source protection area of Qinzhou City.The operation of the ship lock is affected by the salt water flowing upstream.The influencing factors of dam site selection and general arrangement are complicated.This paper compares the site selection and general arrangement of the dam with multiple schemes from the aspects of topography and geology，navigation condition，flood impact，landing condition，impact on surrounding buildings and project investment，etc.Based on the physical model test，the paper optimizes the channel arrangement of the upstream entrance area and connecting section and improves the navigable flow conditions of upstream and downstream entrance areas.Under the condition that the carrying capacity is not lower than the upstream cascade，the water-saving scheme of mutual irrigation and mutual discharge can increase the maximum navigable flow with lower project investment and a better general arrangement scheme.