In this work, the microstructure of the dragonfly wing vein was investigated by the finite element method (FEM). It is a bionic view to simulate the microstructure of the wing vein, which could be used to construct the micro air vehicles (MAVs). From the FEM results, the sandwich structure of the dragonfly wing vein was proved, which could supply more torsional deformation and reduce the weight of dragonfly. And the protein layer in the sandwich structure almost not bear the bending loadings, which could protect the protein not to be destroyed. It could assist us to utilize such design for the new micro air vehicle (MAV), especially ornithopter.