In the ship lock construction of the Longxikou Navigation-power Junction project,problems may occur,such as the safety hazard of residents crossing the river,temporary navigation of the ship lock,and downstream riverbed downcutting.To address these problems,we employ a two-dimensional mathematical model to numerically simulate the downstream flow conditions of the project reach during the construction period and the navigable flow conditions of the upper approach channel of the ship lock in the first flood season of the third phase project.Combining with the specific situations of the project,we propose a temporary scheme for Xinmin passenger ferrying.The results show that the prediction data of downstream riverbed downcutting,the operation plan of the first flood season of the third phase,and the operation plan of the ship lock ensure the safety of the residents on both sides of the river during the construction period.The scheme effectively solves the influence of riverbed downcutting on the ship lock navigation,guaranteeing the unimpeded channel of the Minjiang River during the first flood season of the third phase.