Low hub-to-tip ratio axial fans are widely used in industrial area, the optimization of high efficiency design has always been an objective. Many investigations on axial fan with medium and high hub-to-tip ratio have shown that Computational Fluid Dynamics (CFD) simulation is powerful for verfiying design of axial fans. However, no standard guidelines for low hub-to-tip ratio fan simulations has been discussed. Validation simulations of a fan with low hub-to-tip diameter ratio have been performed by comparing the predicted to experimental aerodynamic performance characteristics. A strategy and guidelines have been formulated for obtaining accurate predictions for such fans. This strategy pays special attention to the trailing edge shape, inlet and outlet boundary conditions, presence of non-aerodynamically shaped blade sections, tip gap and employed turbulence model.