An unmanned aerial vehicle having a fuselage, a water collection and emission equipment, wings, linear reinforcements, a landing gear and a vertical fin. The water collection and emission equipment has buoyancy units, a sealed cabin, a water pump and a water collection and emission pipe. The sealed cabin is detachably connected to the fuselage, and a compartment is arranged in the sealed cabin. The water pump is arranged in the compartment and the side wall of the sealed cabin has at least one concave part which is concave towards the direction of the inner cavity used for slowing down the swaying of water.