The invention discloses a foldable automatic line patrol unmanned aerial vehicle. The bottom of a power box is fixedly connected with the top of a machine body, an inner cavity of the power box is fixedly connected with a fixed plate, the front side and the rear side of the fixed plate are provided with a first air cylinder respectively by penetration, the two sides of the inner cavity of the power box are slidably connected with a sliding plate, and the two sides of the first air cylinder are fixedly connected with the inner side of the sliding plate. The foldable automatic line patrol unmanned aerial vehicle provided by the invention solves the problem that the existing unmanned aerial vehicle does not have an automatic folding function through the cooperation of the machine body, the power box, the fixed plate, the air cylinder, the sliding plate, a chute, a first fixed block, a movable rod, a propeller, a second fixed block, a second air cylinder, a third fixed block, a camera anda motor. The unmanned aerial vehicle has the advantages of automatic folding, a user saves time and labor when folding the unmanned aerial vehicle, the use of the user is facilitated, and the practicability of the unmanned aerial vehicle is enhanced. The friction between support legs of the unmanned aerial vehicle and the ground is improved, and the unmanned aerial vehicle is prevented from slipping when the unmanned aerial vehicle is parked on a smooth ground or an inclined ground.