Aiming at the large plane scale,high water transfer intensity,limited width of downstream common approach channel,possible backflow,oblique flow and other hydraulic problems of Jiantan double-line ship lock,a physical model with a scale of 1:30 is used to study the navigable flow conditions at the outlet of Jiantan double-line ship lock and the downstream approach channel.The results show that it is reasonable to adopt partial lateral drainage arrangement at the sluice of Jiantan double-line ship lock.Adding a permeable water separation wall can weaken the backflow strength of the barrier head.When the double-line lock drains at the same time,the flow velocity in the common approach channel is large,and the flow velocity can be reduced to the standard limit by adopting the mode of cross-peak discharge or reverse operation.After taking the corresponding optimization measures,the hydraulic indexes of the drainage outlet and the lower approach channel of Jiantan Lock water delivery system can meet the design and specification requirements under the design of the most unfavorable head combination condition.The research results can be used as reference for similar projects.