Conical diffuser has been widely used in mechanical and mining engineering.Fully developed and incompressible viscous turbulent flow in a conical diffuser with a total divergence of eight and an area ratio of 4 has been simulated by DHR k-ε turbulence model,its wall functions ·BFC(Boundary Fit Coordinates)approach.Algebraic multigrid method(AMG) and a new five-point scheme were used in this research.The results of numerical simulation are compared with the results obtained by the AMG method and Point-SOR method.The results show that,under the same conditions of calculation and solving precision,the efficiency of numerical calculation for the incompressible viscous turbulent flow can be improved if the AMG method is used.The calculated results agree well with the experimental results.