Abstract: Guiping 2nd lane ship lock is the first 3,000 t class lock on the Xijiang River,in huge size and constructed with complicated techniques,and it will quite improve the traffic capacity of the Xijiang River and make it become the first class waterway.Since its operation,vessels can go through the lock smoothly,the filling and emptying system has good energy dissipation efficiency,the vessel quantity in one lock cycle of the 2nd lane is 2.5 times that of the 1st lane,and the lockage efficiency has been greatly improved.In this paper,the key techniques,such as the lock overall layout,route selection of the rebuilt road,approach channel layout,measures for improving the flow conditions in the entrance area,filling and emptying system,lock chamber wall structure,reducing the influence of the reverse water head to the 1st lane and guaranteeing construction under dry condition in the foundation pit,have been summarized,and they can be used as references for other ship locks.