The kinematics model of the miniature flapping rotorcraft is established.Based on the panel method, the aerodynamic characteristics of the flapping rotorcraft in the unsteady field under low Reynolds number are studied. The aerodynamic characteristics of the wing and the maximum aerodynamic load in one working cycle are obtained. The finite element model of the flapping wing aircraft wing is established. Based on the variable density method and independent continuous mapping（ICM） method, the static and dynamic topology optimization design of the wing is carried out. By changing the wing topology to optimize the wing modal frequency, the suitable flapping rotor aircraft wing topology is obtained with the structural statics and kinetics requirements satisfied. The paper provided a basic idea and research foundation for the wing structure of the flapping rotorcraft.