The invention discloses irradiation-resistance rubber for a nuclear power steam generator blocking plate airbag and a preparing method of the irradiation-resistance rubber. The irradiation-resistancerubber is prepared from, by weight, 100 parts of ethylene propylene diene monomer, 4-6 parts of zinc oxide, 0.5-1.5 parts of stearic acid, 2.5-6.5 parts of anti-aging agent, 0.5-1.2 parts of couplingreagent, 0.5-2 parts of adhesive, 1-3 parts of microcrystalline wax, 2-5 parts of alkyl phenolic resin, 3-7 parts of binding agent, 1-3 parts of aramid fiber, 5-7.5 parts of oligomerized ester, 3-5 parts of polybenzoate, 5-10 parts of dehydroxylation white carbon black, 30-40 parts of anthracene oil carbon black, 10-15 parts of superfine carbon black N110, 15-20 parts of paraffin oil, 3.5-5.5 parts of vulcanizing agent, 0.8-1.5 parts of accelerator and 0.2-1 part of carbon nano-tube-ethyl alcohol mixed liquid. The rubber resists irradiation, has good toughness and can be used for preparing thenuclear power steam generator blocking plate airbag and fill the blank in domestic blocking plate airbags.