In view of the substantial increase of beach risks needing regulation in the upstream channel of the Datengxia hydro-junction due to the change of the operation mode of the hydro-junction in the project proposal and feasibility study stage，we analyze comparatively the lowest navigable stage under the two operation modes and the construction water level before and after the first-stage impoundment，and obtain the lowest navigable stage and the decline caused by excavation，the influence on the channel design scheme and investment，and the construction water level results before and after the first impoundment of Datengxia. The conclusion is that the channel regulation scheme in the reservoir area is greatly affected by the operation mode of the hydro-junction. In the design，the influence of dispatching operation mode on the design water level and design scheme should be analyzed emphatically. Combined with the water storage plan of the hydro-junction，the land reef blasting operation should be reasonably arranged before the water storage to control the investment.