The influence of ducted fan profile parameters to aerodynamic characteristics was investigated. The threedimensional incompressible viscous NavierStokes equations and SST k-ω turbulence model were used to simulate the complex flow of a 2-blade propeller, which was based on the sliding mesh method. To demonstrate the feasibility of the method, the result was compared with the experimental data. The influences of the lip shape, diffuser angle, the height of duct on aerodynamic characteristics and the flow field were analyzed under the condition of hovering and within the limits of 3000 r/min to 8500 r/min. The thrust coefficient was produced by the ducted fan under the condition that the elliptical lip is smaller than the others, and its aerodynamic efficiency is very low. The power coefficient is the smallest when the diffuser angle is 8.2°. The flow separation emerges nearer to the duct under the propeller disk, with the increase of diffuser angle. The sensitivity of thrust coefficient to the change of ducted fan height is low. The power coefficient descends slightly with the increase of height.