Abstract: In order to study the flow force characteristics of a new-type submerged spur dike, a 3D mathematical model is developed by using the fluid calculation software Fluent to study the flow force characteristics of the new-type spur dike with tooth-shaped structures under the conditions of different flow velocities, water depths and dike lengths based on the finite volume method and the free surface capture method. Meanwhile, a physical model with the scale of 1:50 is also designed to make a supplementary verification of the flow force of the new spur dike under the conditions of different dike lengths. The numerical simulation results are in good agreement with the model test results. The distribution laws of the flow velocity and water depth of the spur dike's flow field are obtained, and the flow force response laws of the new-type spur dike with tooth-shaped structures under the conditions of different flow velocities, water depths and dike lengths are analyzed, and the response laws of relative dike lengths and the critical submergence degree to the flow force coefficients via dimensional process are further analyzed. And the sensitivity of relative dike lengths and the critical submergence degree to the flow force coefficients are respectively discussed by means of independent analysis. The research results will provide certain technical supports and scientific guidance for the location of the new-type submerged spur dikes in the 12.5 m deep waterway regulation works in the lower reaches of the Yangtze River from Nanjing.