In view of the bottleneck problem of the lock and dam,this paper summarizes the main key technologies and innovative design of the construction of the ship lock expansion and reconstruction project which includes the general layout involving the retaining of the existing ship lock and the construction of a new large scale ship lock,the design of lock structure,the connecting water system of the new old locks,strengthening of old ship lock,construction cofferdam under the dam etc.The project can not only meet the navigation safety requirement,but also avoid the adverse impact on dam safety,flood prevention and power generation.And it has a typical demonstration effect to solve the navigation obstruction problems in many of our country’shubs.