The large concrete toothed spur dike was applied firstly in the deep-water channel regulation project,and the interaction between the large concrete toothed spur dike and the water flow is not clear.Through the method of theoretical analysis and numerical simulation,the paper studied the backwater characteristics of the new spur dike,the influence of the new type of spur dike on the water flow through the dam was analyzed by comparing with other dam types.Then,the paper discussed the calculation method of the water flow force of the new type ding dam by means of the representation method of the blocking flow.It is found that the new formula for the backwater of the dam can reasonably predict the backwater value of the dam,and due to the existence of foundation bed,the influence of the new type ding dam on the water flow through the dam is small.At the same time,the calculation formula of water flow force represented by blocking flow is more convenient. The introduction of the new spur dike protect water flow,sediment and the ecological balance along the Yangtze River,and the research results can provide scientific theoretical guidance to the design and application of new spur dike provides,which also has reference value to the other new structure design.