A flight imaging system and a method suitable where an unmanned flying object equipped with a visible camera and millimeter-wave radar is used, and a structure imaged by the visible camera and millimeter-wave radar mounted on the unmanned flying object are provided. A drone constituting the flight imaging system is equipped with a visible camera and a millimeter-wave radar. A processor of the drone performs control of the visible camera to capture a visible image of a surface layer of the structure, and control the millimeter-wave radar to transmit a millimeter wave toward the structure and receive a reflected wave of the millimeter wave from the structure, in a case of imaging the structure. During flight of the drone, the altitude of the drone is measured by an altitude meter mounted on the drone, altitude information indicating the measured altitude is acquired, and is used, in flying the drone.