Three-section flapping wing is a new kind of bionic wing, which had better bionic performance compared to existing single-section and two-section wings. In order to realize it, on the basis of single drive mode, a novel mechanism was designed that can realize both flapping and double folding motions. Based on it, analytical and aerodynamic models of three-section flapping wing mechanism were established. Three kinds of typical flight conditions were selected to calculate the aerodynamic changes of three-section and two-section wings. The results show that the mechanism meets the requirements of bionic design. Compared with other flapping wings, the three-section flapping wing mechanism can achieve dexterous and efficient bionic movements and also has better bionic kinetic characteristics and aerodynamic performance.