Irradiation crosslinking of insulation materials for automotive electric wires comprises a mixture of components, including base resin (LLDPE, EVA), compatibilizers, flame retardants, fillers, antioxidants, lubricants, and crosslinking sensitizers. The use of organic montmorillonite and calcium carbonate silica gel fillers, which improve char formation and flame retardant properties, while optimizing component proportions enhances thermal resistance and reduces flame retardant needs.