Longxikou Navigation-power Junction project in Minjiang River is the fourth level of the upgrade of the waterway from Leshan to Yibin of Minjiang River,and the navigable flow condition of the approach channel of the project is an important factor to ensure the safety of heavy and large waterway transportation channels in Sichuan.This paper uses the 1100 physical hydraulic model to conduct tests and analyzes the navigable flow conditions under various navigable conditions.In view of the problem that the navigable flow conditions of the upper approach channel do not meet the requirements of the code,the paper proposes comprehensive engineering measures to improve the navigable flow conditions of the approach channel at the entrance area and increase the maximum navigable safety flow.It solves the navigation safety problem of the upper approach channel and entrance area of the junction,and the research results can provide a reference for similar projects.