Abstract: Overall physical model test was carried out in the aim of improving the navigation flow condition in the downstream of the second ship lock of Dayuandu navigation and electricity junction. The navigation flow condition and its influencing factors in the entrance area of the approach channel of the second ship lock in winding river with tributaries were analyzed. Through many optimization tests and comparisons, a parapet project with a water-resisting wall outside the entrance area in the downstream was proposed. This optimized project meet the requirements of navigation and flood discharge capacity in the entrance area, and the problem of navigation in the shiplock’s downstream is solved. The research provides a scientific basis and reference for similar projects.

Key words: winding river, entrance area, navigation flow condition, model test