The invention discloses equipment and a method for installing wires of an overhead power transmission line, and belongs to the technical field of cable or electric wire installation. The equipment for installing the wires of the overhead power transmission line comprises an aircraft, a steel wire rope, pulley assemblies, a take-up and payoff device and a wire installation device, wherein the pulley assemblies are installed on a first electric pole and a second electric pole at two ends of a construction area section; the steel wire rope is dragged by the aircraft to bypass the pulley assemblies, and the two ends of the steel wire rope are used for controlling the tensioning force through the take-up and payoff device; and the wire installation device walks along the steel wire rope so as to drag the wires to span the overhead of the complicated construction area section. According to the equipment for installing the wires of the overhead power transmission line disclosed by the invention, the installation of the wires of the overhead power transmission line spanning the complicated area sections such as rivers and mountains is realized, the construction cost is reduced, the work efficiency is improved, the construction period is shortened, and the damages for the wires in the installation process are avoided.