With the rapid development of national economy and a growing demand for water transportation, inland waterway transport has risen to a national strategy level. Therefore, we have to settle some shipping bottlenecks for parts of inland water transportation. The Gongdaying lock expansion plan for Youdungang waterway regulation project in Shanghai is analyzed by comparing several different expansion plans, and the current plan is determined to build a new lock on the east side of the old lock. Meanwhile, some related key technical problems are solved, such as layout plan and hydraulic structures. The experience obtained in this project provides reference for solving the similar bottleneck problems hampering inland waterway transportation.