The invention discloses a guide pulley dedicated to an unmanned aerial vehicle. The guide pulley comprises a main body shell (1), wherein one end of the main body shell is connected with a side plate (2); the other end of the main body shell is connected with a connecting piece (3); the lower end of the connecting piece is connected with a pothook (4); a traction rope pulley (7) is mounted on the pothook; an electric cable pulley (6) is mounted between the main body shell and the side plate; a first spring (8) and a position-limiting rod are mounted in the main body shell; a lockpin (9) is arranged on one side of the first spring and is connected with a second spring (11); a pulley block is mounted in the main body shell; a steel wire rope (12) is arranged on the pulley block; one end of the steel wire rope is connected with the lockpin; and the other end of the steel wire rope is connected with the connecting piece. The guide pulley and a jettison system based on the guide pulley can precisely position through the unmanned aerial vehicle, and the guide pulley is directly adopted to transport a rope ladder or other tools to designated positions, so that the burden of a worker is greatly lowered and the risk of equipotential hot-line work is also reduced.