Abstract: Multibody vehicle widely exists in the fields of aerospace and weapon system. There are three main types for the multibody vehicle system. Firstly, multiple vehicles are in close proximity flight that do not touch each other, such as formation flight and towed flight. Secendly, multibody vehicle are in contact with each other or combined to flight as a whole, such as aircraft-store carriage, the booster-flight of multistage vehicles, etc. Finally, multibody vehicle is in the relative motion after recovery or separation, such as aircraft-store separation, stage separation of multistage vehicles, etc. Multibody interference or interaction universally exists in the flowfield of multibody vehicle during steady or unsteady flight and dynamic separation, which makes the flow physics or characteristics of multibody vehicle different from isolated-body vehicle, especially in supersonic and hypersonic flow. There are multiple shock-wave reflection and diffraction, interference or interaction between shock-wave and vortex, shock-wave and boundary layer among multibody vehicle, which can significantly change the aerodynamic characteristics of multibody vehicle. The concept of “multibody aerodynamics” is advocated to summarize the field of multibody vehicle, and its basic connotation, application fields and flow characteristics of typical multibody configurations are explained, in order to point out the direction and ideas on aerodynamics and separation dynamics of multibody vehicle for the future research.