The general design and layout of the double line five step ship lock , the water delivery technique for high head ship lock, the key technical problems of fully lined ship-lock and the monitoring techniques for large scale miter gates and hoisting equipment under complicated operation conditions of the Three Gorges Project (TGP) are introduced. Since the operation of ship lock in 2003, the operation practice has proved that the design techniques are advanced, rational and reliable. The design and construction of the fully lined ship lock promotes the development of design theory and practice of ship lock projects, which makes the construction technology of ship lock in the world reach a new level.