The invention discloses an obstacle clearing device for an overhead transmission line, comprising an unmanned aerial vehicle; the unmanned aerial vehicle comprises an unmanned aerial vehicle main body and at least two sets of rotor wings arranged on the unmanned aerial vehicle main body; the rotor wings comprise support rods and propeller vanes connected to the support rods; any one set of rotor wings comprise two rotor wings; the central axes of the support rods of the rotor wings are located on the same straight line; a camera for photographing foreign bodies on the overhead transmission line is arranged on the unmanned aerial vehicle main body; a laser device for clearing the foreign bodies on the overhead transmission line is arranged on the unmanned aerial vehicle main body; the laser device is fastened at the bottom of the unmanned aerial vehicle main body; when the unmanned aerial vehicle takes off, the camera detects the foreign bodies on the overhead transmission line, the laser device is adjusted to certain reliable distance capable of ablating the foreign bodies; the laser device is started to ablate the foreign bodies; the obstacle clearing device for the overhead transmission line of the invention can clear the obstacles accurately, further reduces the difficulty of obstacle clearing work and promotes the working efficiency.