The invention relates to EPDM (Ethylene-Propylene-Diene Monomer) for a sealing ring and a vulcanization method thereof. The EPDM for the sealing ring comprises the following components: non-oil-filled raw ethylene-propylene rubber, oil-filled raw ethylene-propylene rubber, ZnO, an anti-aging agent, general purpose black, sulfur, flavorless DCP and a cross-linking agent TAIC. In the cross-linking process, both C-C bonds and S cross-linking bonds are contained, the compression deformation rate is low, and the tear resistance is improved; the oil-filled raw ethylene-propylene rubber and the non-oil-filled raw ethylene-propylene rubber can be combined, so that the compression deformation performance is guaranteed, usage of plasticizer oil in the formula is reduced, and the rubber is easily and uniformly mixed and is high in liquidity, thin in rubber edge and easy to tear; and moreover, the product has the advantage that peroxide vulcanizedethylene-propylene rubber is low in permanent compression deformation rate, and the problem that peroxide vulcanizedEPDM products are difficult to tear is solved, so that the performance and production efficiency of the product are improved.