The invention discloses a device for launching a fire-extinguishing bullet at a high-rise building by an unmanned aerial vehicle. The device for launching the fire-extinguishing bullet at the high-rise building by the unmanned aerial vehicle comprises an unmanned aerial vehicle, a launching box, explosive fire extinguishing bullets, a high-pressure gas cylinder and a remote controller. The unmanned aerial vehicle is provided with rotating wings, a conventional camera, a positioning sighting device, an infrared sighting device and a laser sighting device to facilitate the operation in a complexenvironment such as night. The launching box is fixed to a landing gear under the unmanned aerial vehicle by a box suspension device. A plurality of launching barrels are arranged in a front bin of the launching box. The high-pressure gas cylinder and a pressure indicator are arranged in a rear bin of the launching box. High-pressure gas enters a high-pressure gas distribution box and a pluralityof gas outlet valves. The remote controller controls launching of compressed gas. The remote controller is used for launching the explosive fire extinguishing bullets one by one to enter a fire-extinguishing place of the high-rise residential building and extinguish fire. The device for launching the fire-extinguishing bullet at the high-rise building by the unmanned aerial vehicle is not restricted by the terrain and the distance between buildings, and can fly up and down to north, south, east and west directions of high-rise residential buildings at high speed and in a maneuvering mode, sothat the fire-extinguishing in the high-rise residential building can be carried out rapidly, accurately and efficiently, the defect of fire fighting truck in high-rise building fire-extinguishing isovercome, and the unmanned aerial vehicle high-rise building launching fire-extinguishing bullet device is suitable for fire departments at all levels such as cities, counties, townships and communities.