The Kou’anzhi waterway is an important part in the second phase of the regulation project of 12.5 m deep water channel from Nanjing to the mouth in the Yangtze River. The upper part belongs to braided rivers of many branches,and the lower part is straight rivers. Moreover,the upper part locates in the curved channels,into which Huaihe river flows,the flood-plain changes violently,and the channel conditions are affected by many complicated factors. The large inflow of Huaihe river is the important formation cause for the Luochengzhou shoal. Using the numerical models,we investigate the effects of the Huaihe river inflow on the deep water channel in Kou’anzhi waterway. The simulated results show that the inflow of Huaihe river causes the amplitude and range of deposition in the Sanyiqiao beach above the estuary of Huaihe river and in the designed navigation channels of 12.5 m at the left branch increasing. Under these influences,the minimum width of the isobath below 12.5 m in the designed navigation channels at the left branch of Luochengzhou is mildly greater than that without regard to the Huaihe river inflow,the channel width in the designed navigation channels,dissatisfying with 12.5 m of water depth,slightly decreases in the Gaogang beach,while the similar channel width in the lower part of the right channel of Manyusha has a slight increase from that without considering the Huaihe river inflow.