The confluence of the Maoping River as a tributary of the Pinglu Canal in natural conditions has a significant influence on the navigation conditions of the canal，and there are severe adverse hydraulic phenomena such as lateral flow and backflow in the confluence area，which affects navigation.Aiming at the navigation conditions of the confluence area of the Maoping River into the Pinglu Canal，this paper adopts three-dimensional numerical simulations to study the navigable flow conditions in this area under different flow combinations.Meanwhile，by combining the shortcomings of the design scheme in navigable conditions，it analyzes two aspects of incoming tributary water adjustment and confluence section widening.The results show that the optimized scheme yields sound results and improves navigable conditions of the canal，and the hydraulic indicators such as lateral flow velocity and return flow velocity can both meet the requirements of the relevant standards.