The invention discloses a high-resilience transformer sealing gasket and a preparation method thereof. The high-resilience transformer sealing gasket is prepared from 70-80 weight parts of methyl vinyl silicone rubber, 20-30 weight parts of polyurethane rubber, 15-20 weight parts of hexamethyldisilazane, 30-40 weight parts of fumed silica, 4-6 weight parts of diphenylsilanediol, 1-2 weight parts of zinc oxide, 2-3 weight parts of stearic acid, 1-2 weight parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 0.5-1 weight part of dicumyl peroxide, 2-3 weight parts of bis-(gamma-triethoxysilylpropyl)tetrasulfide, 1-2 weight parts of an antiager RD, 2-3 weight parts of an antiager TNP, 1-2 weight parts of an antioxidant 1010, 10-15 weight parts of coumarone resin, 5-10 weight parts of nanometer potassium feldspar, 4-8 weight parts of organobentonite, 6-12 weight parts of mica powder and 3-5 weight parts of a composite filling material. The high-resilience transformer sealing gasket is soft and smooth, has no toxicity and smell, has excellent high temperature and low temperature resistance, excellent compression resilience and high mechanical strength, can be used at a temperature of -70-250 DEG C for a long time, and does not age, deform and crack.