Abstract: The unsteady aerodynamics associated with flapping flight of flapping-wing Micro Air Vehicles (MAVs) was studied using computational fluid dynamics.A three-dimensional flapping wing model was established for the MAV,which mimicked biological locomotion,such as insect flight.The Arbitrary Lagrangian Eulerian (ALE) finite element method with ANSYS/CFD was used to solve the Navier-Stokes equations numerically.The solution proves that the leading-edge vortices could generate enough lift to support a typical flapping MAV.Based on the bionics aerodynamic model,the variations of different parameters such as flapping amplitude,pitching amplitude and flapping frequency of the MAV were studied.Finally,exploratory flapping wing wind-tunnel test and flight test prove,in certain degree,the feasibility of the method presented.The modeling method,as well as the conclusions is suitable for the design and analysis of flapping-wing MAVs.