The invention discloses a suspended type automatic fire extinguishing device for a high-rise building. The suspended type automatic fire extinguishing device comprises a fire control cabin, an ammunition feed system, a launching system and a plane self-balance device. The fire control cabin comprises an aluminum section frame, large universal wheels and a propulsion propeller. The ammunition feed system comprises a magazine, an ammunition drum, a support, an ammunition drum outer box, a groove wheel driving wheel, a groove wheel driven wheel and a servo motor. The launching system comprises a launching gun barrel, an air cylinder, a connecting rod, a first servo motor, a buckle, a plane cam, an impact pressing block, a propulsion seat, an energy storage spring, a linear guide rail and a lead screw nut. The plane self-balance device comprises a vertical transmission mechanism and a transverse transmission mechanism. The transverse transmission mechanism is composed of a balance block, a lead screw nut, a lead screw, a linear guide shaft, a center shaft and a second servo motor. The suspended type automatic fire extinguishing device is simple in structure, safe, reliable and high in automation degree, and the problem that the fire protection firing range of a ground fire extinguishing system to the high-rise building is insufficient is solved; and a mechanical launching device is adopted, so that safety is enhanced, and the fire protection bottleneck of the high-rise building is broken through.