Abstract: crank-rocker flapping mechanism inspired by insects is proposed based on theanalysis of the normal flapping mechanism. The parallel crank-rocker is a kindof spatial linkage mechanism, in which due to the two parallel crank-rockersand the wing control mechanism between them, the flapping mechanism can notonly keep the symmetry of the left and right wings during the motion,but also provide an accurate control of stroke angle and angle of attacksimulation. MATLAB nonlinear optimization toolbox is employed to achievethe motion optimization. A scaled model is developed based the optimizationand the reference motion of the model is a hovering flight Hawkmoth. Theforce measurement results reveal that the flapping mechanism can providea high unsteady lift force, and the flapping mechanism is shown to be oneof a practicable and novel design in flapping Micro Aero Vehicle research.