With the implementation of the two shoal regulation projects of Luochengzhou and Manyusha in the 12.5 m deep water channel below Nanjing of the Yangtze River,the external conditions of the Gaogang side beach have changed.The channel navigation conditions of Gaogang reach at the end of 10 years are predicted by means of riverbed evolution analysis and numerical simulation,and the evolution trend of Gaogang side beach and its influence on navigation in deep water are analyzed.The results show that:in the future,the river regime of Yangzhong reach will be basically stable,and the Gaogang side beach will not be silted up or washed away;the channel conditions of the upper middle section of the Gaogang reach can meet the navigation conditions of the deep-water channel,but there are slight navigation obstacles in the lower section of the Gaogang reach.