Taking Xicheng canal Xinxia Port ship lock as an example,this paper puts forward two kinds of plane layout schemes:staggered double-line arrangement and parallel double-line arrangement.Through comparison and analysis,it shows the innovation and superiority of the staggered double-line arrangement in this project.It provides a reference for the design of double-line ship lock.At the same time,the original design scheme of the double-line lock chamber structure and the upstream and downstream approach channel building is analyzed in detail,and the optimization scheme is put forward to adapt to the actual situation of the site and effectively improve the engineering economy.