Method for enhancing and restoring insulation breakdown of crosslinked polyethylene medium-voltage cable

The invention discloses a method for enhancing and restoring insulation breakdown of a crosslinked polyethylene medium-voltage cable. The method comprises the following steps of S1, cutting an annular opening of 10-15 centimeters in an annular round surface of the cable to deeply contact a conductor (1); S2, cutting a fracture surface to a barbell shape by a cutter, and slowly and smoothly cutting a restored slope surface (6) by a special steel knife and a glass sheet of 2 millimeters, wherein a part of 10-15 centimeters is exposed at an intermediate conductor (1), no sharp cover and burr are required, and an internal shielding layer (2) is exposed; S7, wrapping a layer of copper belt with a thickness of 0.1 millimeter at the outermost layer in a half lamination way; S8, braking the copper belt, where a restore part of a braking edge is mainly concentrated; and S9, pouring a nanometer macromolecule restore liquid to two ends of a conductor wire core after restore by an adapter. The method has the advantages that the restore method is simple and reliable; by enhancing and restoring an insulation damage, a scrapped cable can b effectively utilized, the insulation performance of the cable is improved, the fault probability of a cable body is reduced, and the stable running of a cable system is greatly facilitated.