Abstract: Flutter is a kind of aeroelastic dynamic instability phenomenon, which is common in aircraft wings, tails, bridges and other elastic structures. Once flutter occurs, it will cause destructive damage to the structure. This paper first introduces the basic concepts and characteristics of flutter, as well as the commonly used flutter research methods in the engineering field. Taking the NACA0012 elastic straight wing with aspect ratio of 16 as an example, the flutter velocity and flutter frequency are introduced. Then the causes of structural flutter are discussed, and the application of stability analysis method based on reduced-order model in the mechanism study of laminar separation flutter is described in detail. Finally, the control measures to prevent and avoid flutter are introduced.