The Yuan River is a primary tributary of the Ganjiang River.The middle and lower reaches of the Yuan River are meandering，which belong to a transitional river between hills and plains.The average bed slope is 0.2‰，and the flood rise and fall fast.The proposed Longweizhou project is the last step of the Yuan River channel upgrading project.The upstream and downstream reaches of the dam site are continuous bends，and there exists protruding banks deflecting flow and point bars.The complex boundary conditions make it difficult to design the ship-lock.The overall physical model of Longweizhou project is constructed to carry out the tests of navigable water flow conditions of the ship-lock.Under the current boundary conditions，the ship-lock is difficult to achieve safe navigation under the 20-year flood conditions required by the standard.Thus，the study of improvement measures is carried out to determine the operation regulation of lock gates and maximum navigable discharge suitable for ship navigation in combination with the flood characteristics of the Yuan River，which provides the basis for engineering design and management.When constructing high-grade ship-locks on rivers with short flood duration，it is recommended to adopt the maximum navigable discharge for ship-locks management and optimizing the design of the partition wall，berthing dolphin and navigation wall to ensure navigational safety and save investment costs on the basis of satisfying the cargo volume through the ship-lock.