A photocrosslinking process for polyethylene and its industrial irradiation apparatus has recently been developed and used successfully in the manufacture of thin wall crosslinked polyethylene-insulated wires. Polyethylene (PE) resin with the desired amounts of additives, such as photoinitiator, multifunctional crosslinker, and antioxidant is mixed homogeneously. The admixture of PE is granulated, and then extruded on a conductor wire. The coated PE layer in the melt is subsequently irradiated in a specially designed UV irradiation apparatus for 5 to 10 s. The studies show that the photocrosslinked PE-insulation high voltage television wires produced by this new technique possess excellent electrical and mechanical properties and much lower operating cost compared with wires produced by the electron beam crosslinking technique.