The invention discloses a distribution overhead line electroscope based on an unmanned aerial vehicle, and aims to provide the distribution overhead line electroscope which not only can reduce the labor intensity of the distribution overhead line electroscope so as to ensure the safety and reliability of the electroscope, but also can effectively solve the problem that the unmanned aerial vehicleis unbalanced due to external force interference in the contact process of the unmanned aerial vehicle electroscope and the distribution overhead line. The distribution overhead line electroscope based on the unmanned aerial vehicle comprises the unmanned aerial vehicle, wherein the middle part of a frame of the unmanned aerial vehicle is provided with a ball head hole with openings at the upper end and the lower end; a test pen, wherein the test pen comprises an insulating rod, and the insulating rod penetrates through the ball head hole; a ball head, which is rotationally matched with the ball head hole, is arranged on the insulating rod; the insulating rod is rotationally arranged on the ball head hole of the frame through the ball head, and the gravity center of the test pen is positioned below the frame.