The invention discloses a butyl rubber for wrapping a capacitor case, which is prepared from the following raw materials: butyl rubber (BBK232), LANXESS Deutschland 9650 ethylene propylene diene monomer, poly-4-methyl-1-pentylene, zinc oxide, nano fluorite powder, nano bentonite, attapulgite, anti-aging agent NBC, anti-aging agent OD, polyamide wax micropowder, accelerator TMTD, accelerator CZ, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, isopropyl tri(dioctylpyrophosphate)titanate, antioxidant 1035, carbon black N339, N660 carbon black 15-25, dibasic lead phosphite, tributyl citrate, stearic acid, coumarone, propanediol sebacate polyester, benzenesulfonyl hydrazide, ferrocene and modified kieselguhr. According to the reasonable raw material formula, the produced rubber has favorable comprehensive properties and strong binding property with metal; and the rubber has high mechanical properties, fatigue resistance, dynamic ozone resistance, aging resistance and the like, thereby providing a high-intensity protective function for the capacitor.