In the existing model of the Yangtze River estuary section,through movable bed model experiment,the influences on 12.5 m deepwater channel phase I project of Tongzhou shoal west channel regulation project are studied.After implementing the west channel regulation project,the -8 m excavation scheme and no excavation scheme are both good for the maintenance of deepwater channel depth,but Tongzhou shoal beach ditches on the left side of the deepwater channel are eroded.With the increase of the excavation depth,the impacts on the deepwater channel increase gradually.When the excavation is to -12 m or -14.7 m,the influences reach Yingchuangang,but beach ditches are slightly deposited,which are favorable for the stability of the sand body.This study proposes that the excavation depth should not be too large,and the downstream extension engineering of Tongzhou shoal submerged breakwater should be implemented as soon as possible.