Abstract: The solution variables are stored at the triangular circumcenters based on unstructured meshes,which can avoid discretization errors made by all kinds of correction methods used in non-orthogonal meshes.Rhie-Chow's momentum interpolation method is adopted here to derive water level correction equation based on the SIMPLE method and a detail discretization equation is showed.The momentum equation is discretized by the power law scheme which has good numerical property.The flow phenomenon and the measured results agree with the numerical results very much,and the characteristics volumes of the eddies of the upper and down reaches around apur dike are simulated successfully.