The dry season water level is recording low in main branch channel of Ganjiang River sink,in which has adverse impact on the utilization of water resources,navigation,waterfront landscape and water environment.And it will remain gradual decrement trend in the future.This research establishes a 2-D flow and sediment mathematical modal through analyzing the water and sediment characteristics of main branch channel in recent years.It next constitutes a boundary condition by selecting flow and sediment data of 1992,2002,2004,to conduct numerical simulation research.Then,it mainly comparatively analyzed the variation of erosion-deposition,flood and dry season water level,depth of channel and utilization of point bar before and after the implementation of those regulations.In the end,it concluds that those regulation projects can play a very good effect on controlling dry season water level,maintaining navigable depth,improving waterfront landscape and improving the utilization ratio of point bar to promote the local marine economic development.