Erosion of sluice is a common problem in water conservancy projects. Many researchers have conducted systematic studies on this problem. The results showed that application of scrap tires was an effective approach to increase the roughness of apron and thus reduce erosion. By comparison and analysis of the different turbulence models, numerical methods, grid scale and wall surface methods, finally the RNG k-ε turbulence model and PISO algorithm were used, the whole flow field was divided into 672700 grids, and standard wall functions were used to deal with the boundary condition to calculate the flow field of scrap tires in energy dissipation and erosion control under sluice. The calculation results were in good agreement with the model test results, indicating that the model could be used to the flow field with enhanced roughness.