Thin film covered winding wire is made of oxygen-free copper rod or electrical round aluminum rod with a specific mold suppress or wire drawing cooling treatment, and then coated in copper (aluminum) conductor with two or more layers of film (including polyester film, polyimide film, and so on) winding, suitable for oil-immersed transformer wiring and similar electrical winding. Electric bare copper (aluminum) wire produced by the extrusion technique is a good material for the manufacturing of thin film coated wire.