Abstract: Insects, birds and bats have superb flying ability. They are the main imitators of a flapping-wing aircraft. In recent years, a great progress has been made in the field of flapping-wing aerodynamics. This paper summarized the main research results, and focus on the recent advances in flapping-wing aerodynamics, including the flapping-wings lift mechanism of insects, birds and bats, the effects of wing morphological parameters and microstructures, wing flexibility, dynamic deformation, wing-wing interference, wing-body interference, inter-individual interference, and ground effect on the flapping wing aerodynamics. We also introduced the research progress of aerodynamic research on bionic flapping-wing aircraft design. At the end, the main problems and challenges faced by flapping-wing aerodynamics are presented.