The invention belongs to the field of agricultural equipment, and particularly relates to a plant protection unmanned aerial vehicle capable of automatically controlling the amount during turning. Theplant protection unmanned aerial vehicle comprises an unmanned aerial vehicle body, a cavity is formed in the side wall of the lower end of the unmanned aerial vehicle body, a water tank is sleeved with the cavity in a connected manner, the water tank communicates with a concave pipe through a communicating pipe, and water outlet ends at the two sides of the concave pipe communicate with nozzles;and two hollow rotating rods are rotatably connected to the concave pipe, a wind wheel is fixedly connected to one of the hollow rotating rods, and transmission is conducted between the two hollow rotating rods through a transmission mechanism. According to the plant protection unmanned aerial vehicle, when the unmanned aerial vehicle inclines, the pressure of liquid at the two sides of a pipeline is changed, automatic adjustment of water outlet end openings is achieved, and the spraying uniformity of the nozzles at the two sides is guaranteed; and meanwhile, by means of an electromagnetic induction principle, filtering layers vibrate at intervals, the filtering effect is guaranteed, and dissolution of medicine powder is accelerated.