Five novel heteropolyacid-based ionic liquids ［BSbBim］₄SiW₁₂O₄₀(4a), ［BSbBim］₃PW₁₂O₄₀(4b), ［BSbBim］₃PMo₁₂O₄₀(4c), ［CMbBim］₄SiW₁₂O₄₀(5) and ［BbBim］₄SiW₁₂O₄₀ (6) were synthesized by reaction of heteropolyacid and ［BSbBim］(1), ［CMbBim］Cl(2), ［BbBim］Br(3), which were prepared from 1-butyl-1H-benzo［d］imidazole. The structures were characterized by ¹H NMR, ¹³C NMR and IR. Oxidation of cyclohexene to adipic acid with hydrogen peroxide catalyzed by 4~6 were investigated. And the results showed that 4b has the best catalytic activity. The yield of adipic acid was up to 71％ under the optimized conditions that cyclohexene was 20 mmol， 4b was 0.16 mmol, n(cyclohexene) : n(H₂O₂) : n(ILs)=1 :4.4 :0.008.