The present invention discloses a device of insulator hydrophobicity detection based on an unmanned aerial vehicle. The device comprises an unmanned aerial vehicle which is provided with a high-pressure water tank, the high-pressure water tank is connected with an atomizing nozzle through a water transmission pipeline, the water transmission pipeline is provided with a solenoid valve, and the control end of the solenoid valve is connected with the signal output end of the controller of the unmanned aerial vehicle; the device also comprises an optical fiber lens arranged on the unmanned aerial vehicle close to the atomizing nozzle, and the signal output end of the optical fiber lens is connected with the signal input end of the controller; and the controller is connected with an infrared distance meter and a wireless communicator, and the infrared distance meter and the wireless communicator are arranged at the body of the unmanned aerial vehicle. The present invention further discloses a method of insulator hydrophobicity detection based on an unmanned aerial vehicle. The disc surface of a composite insulator can be extracted in a control module on the unmanned aerial vehicle, and the obtained hydrophobicity grade of the composite insulator is sent ground workers so as to provide a new composite insulator hydrophobicity intelligent detection scheme.