In view of the navigation condition problem at the connecting section of Fuchi’s second-line ship lock with the Yangtze River，we adopt the two-dimensional numerical simulation experiment and the simulation experiment of ship handling to study flow conditions，ship handling，and ship navigation trajectories under multiple working conditions. According to the disadvantages of the design scheme in navigation conditions，we propose two measures for optimization：One is to widen the dimension of the entrance south coast，and the other is the adjustment of navigation trajectories. In other words，under low flow rates，ships heading downward could enter the ship lock as early as possible，and under large flow rates，the ship could turn round in a suitable position downstream to enter the ship lock with counter-flow. The results indicate that the optimized scheme can improve the navigation conditions of the connecting section and reduce the risk of ship handling，and the maximum navigable flow rate is increased from 54 100 m3/s to 68 200m3/s，which determines the reasonable flow parameters for engineering design.