Provided is a preparation method for polymerization-type asymmetric hindered phenol anti-oxidant resins. The preparation method comprises steps: with strong acid resins as catalysts, and benzene or cyclohexane as a solvent, p-methylphenol and dicyclopentadiene are subjected to a polymerization reaction to form phenol-type petroleum resins; the phenol-type petroleum resins, saturated alcohols with one to three carbons and isobutanol are subjected to an alkylation reaction to form polymerization-type asymmetric hindered phenol anti-oxidant resins in presence of phosphoric acid and an active component nickel-containing alumina catalyst; the alkylation reaction products are subjected to reduced pressure distillation to remove oligomers, the solvent and the unreacted raw materials to obtain polymerization-type asymmetric hindered phenol antioxidant resin products, and the yield is about 90%. The preparation method has obvious positive effects, through asymmetric substituent groups antioxidant effects are raised. Compared to traditional phenol antioxidants, the synthesized polymerization-type asymmetric hindered phenol antioxidant resins are advantaged by high antioxidant activity, high heat stability, extracting resistance, compatibility, non-toxic and environmentally friendly characteristics.