The invention discloses a high-load all-terrain fixed-wing unmanned aerial vehicle device. The high-load all-terrain fixed-wing unmanned aerial vehicle device comprises a frame body, a landing gear, adriving device, a right wing, an elevator, a rudder, a flight control system, a left wing, pesticide spraying devices and atomizing and spraying devices. According to the high-load all-terrain fixed-wing unmanned aerial vehicle device, by arranging the right wing and the left wing, the spraying width can reach 40 m; by arranging the landing gear, the high-load all-terrain fixed-wing unmanned aerial vehicle device is suitable for taking off and landing on various cement hard runways, lawn runways, grasslands, beaches, rural highways and hard muddy ground; by arranging the driving device, the advantages that the energy density of gasoline is higher than that of the battery, the refueling is convenient and rapid and so on are sufficiently utilized, the preparation for re-operation can be finished within several minutes, and great wild adaptability is realized; by arranging the flight control system and by using a driverless technology, the production rate is increased, and the ever-increasing modern industrial agricultural operation is satisfied; and by arranging the atomizing and spraying devices, the pesticide liquid drops can be accurately controlled so that the pesticide liquid drops can sufficiently adhere to the all surfaces of crops.