Flapping wing air vehicle is the latest technological achievement of the aviation industry, which is still maturing as a miniature of large aircraft before finally achieving the finest development. By mimicking the nature, parametric structural modeling of a flapping wing, made of composite membrane and aluminum alloy support beam is numerically investigated adopting commercial FE code Ansys. A flapping cycle is divided into twelve segments, and for each segment, the maximum stress, first ply failure and the deformation are studied. It is found that the fiber orientation angle has the highest impact on the structural properties during a flapping cycle, where improper stacking sequence will cause failure to the wing. Moreover, increasing the ply thickness has a positive impact on the overall structural performance of the model. Finally, appropriate support beam orientation can further improve the structure by increasing the stiffness and reducing the maximum stress significantly without increasing the overall weight of the wing.