The invention discloses a repair structure and a repair method of a corrosion-proof insulating layer of an insulating pipeline, and belongs to the technical field of oil gas pipeline corrosion control. The repair structure comprises a viscoelastic body adhesive tape layer, a polyurethane foam layer and a hot baking pressure-sensitive adhesive tape layer; the viscoelastic body adhesive tape layer coats the outer surface of a pipe body of to-be-repaired area of the insulating pipeline, and extends to the parts of the outer surface, located in non-repair areas of the insulating pipeline, of an outer protective layer, and the extension length is 60-80mm; the polyurethane foam layer coats the viscoelastic body adhesive tape layer, and the two ends of the polyurethane foam layer are connected with the parts, located in the non-repair areas of the insulating pipeline, of the insulating layer; and the hot baking pressure-sensitive adhesive tape layer coats the polyurethane foam layer and extends to the parts of the outer surface, located in non-repair areas of the insulating pipeline, of the outer protective layer, and the extension length is 80-120mm. The repair structure has the excellent sealing property and waterproofness, and on the premise of ensuring the insulating property, the pipe body of the insulating pipeline effectively is prevented from being corroded.