The invention relates to an arc extinguishing shell material of a motor protection controller. The material is formed by the components by weight, and the formula is composed of polyethylene, polyvinylidene fluoride, bentonite, sepiolite, attapulgite, magnesium oxide, aluminum oxide, strong base, mica, calcium metasilicate, a modifier, a fire retardant, natural rubber, stearic acid, diacetyl peroxide, calcium carbonate, drying oil alkyd resin, white carbon black, antiager, sulphur, polymethyl methacrylate, composite environment-friendly heat stabilizer, graphite, polyethylene wax, lubricant, carbon fibers, calcined clay, talcum powder, an antioxidant, a silane coupling agent, zinc stearate, antiager N-phenyl-N`-isopropyl-p-phenylenediamine, dicumyl peroxide, vulcanization accelerator 2,2`-dithio-dibenzo thiazole, vulcanization accelerator zinc oxide, a mixture of stearic acid and fire retardant decabromodiphenyl ethane.