The invention provides a rotary festoon lamp acoustooptical device on a model airplane, belonging to a sport entertainment model aircraft. Color light-emitting tubes and acoustic equipment are arranged on the positions which are seen easily on the body and wings of the model aircraft and propellers, therefore, when in flight, favorite songs and analog sounds can be heard in the air, and when in night flight, the light-emitting tubes arranged on the propellers rotate to form color light rings with different sizes, thus adding a beautiful and splendid view for night sky. In addition, operators can judge the flight direction and high-low orientation of the model airplane through the fixed festoon lamps and rotary festoon lamps on the model airplane in night flight. The rotary festoon lamp acoustooptical device on the model airplane has the advantages of enabling the model airplane to adapt to the flight environments in day and at night, greatly attracting and increasing the interests of people in the model airplane, and playing a promoting role in wide development of model airplane activities and promotion and popularization of model airplane equipment.