The invention relates to a fire-fighting unmanned aerial vehicle for electric high-voltage overhead lines, which includes a main body of the unmanned aerial vehicle, a support platform, an electric turntable, a redundant parallel mechanism and a fire extinguishing device; the support platform is located at the center of the upper end of the fire extinguishing device, and the support platform It is a "Y" structure, the lower end of the support platform is fixedly connected with the fire extinguishing device, the upper end of the support platform is connected with the lower end surface of the electric turntable, the redundant parallel mechanism is located between the electric turntable and the main body of the drone, and the lower end of the redundant parallel mechanism is connected to the electric turntable The upper end faces are connected, and the upper end of the redundant parallel mechanism is connected with the main body of the drone. The invention can carry out high-altitude fire-fighting and fire-extinguishing operations when a fire occurs on an overhead high-voltage line, and has a high degree of automation, stable and flexible flight during fire-extinguishing, a large range of fire-extinguishing jets, high fire-extinguishing efficiency and high safety, and solves the danger of manual fire-fighting and fire-extinguishing of overhead high-voltage lines big question.