The condition of the flow at the lock entrance area affects directly the safety of the ship in navigation.To counter the problems such as the poor flow condition and the big transverse velocity at the entrance area and connection segment in Likou hydro-junction,we put forward optimization measures including setting shallow dam on the upstream of the dam axis,adjusting the river regime and building guiding dikes for flow diversion based on the establishment of the integral hydraulic model test.The result shows that the flow regimes of the entrance area and connection segment are obviously improved by optimization measures,and the navigation flow condition meets the requirement of the specification.The ship model navigation experiment shows that the maximum navigable flow Q20%=4 661 m3s.The feasibility of engineering and safety of navigation under this plan is also demonstrated.