According to the size of steep slope segment,two types of auxiliary energy dissipation which include continuous internal concave step and discontinuous outer convex step can be set in the spillway so as to increase the friction and drop flow of discharge in steep segment, reduce the flow velocity，and increase discharge energy dissipation rate.Based on the test of hydraulic model,the paper compared and analyzed the discharge flow pattern and energy dissipation rate of continuous internal concave step and discontinuous outer convex step with slope 1∶1.5 in steep slope section of spillway.The experiment shows that in the same steep slope condition of steep segment, the number of discontinuous outer convex step is significantly less than that of continuous inner concave step,but the roughness of outer convex step of unit root number is relatively larger, and the discharge energy dissipation rate of outer convex step is greater than that of internal concave step. Therefore, when the slope i of spillway steep segment is equal and less than 1∶1.5,if the project layout conditions permit, the discontinuous outer convex step should be chosen priority so as to obtain the larger discharge energy dissipation rate,and the step type can also be simplified and the engineering construction can be facilitated in the same time.