The invention discloses a corrosion-resistant seal component based on montmorillonite modification and a preparation method of the seal component. The preparation method comprises the following steps: mixing montmorillonite suspension with a mass concentration of 0.2-0.3%, a surfactant and sodium dodecylsulfate and performing heating with stirring, and performing filtering to obtain modified montmorillonite; mixing ethylene-propylene-diene terpolymer rubber and the modified montmorillonite and performing first blending to obtain a mixture M; mixing the mixture M, calcium carbonate, stearic acid, a silane coupling agent, an accelerator and sulphur to obtain a mixture and performing second blending on the mixture to obtain a mixture N; and compressing the mixture N to a green body by a two-roll open mill and performing sulfuration on the green body to obtain an anti-aging sealing material. The corrosion-resistant seal component based on montmorillonite modification solves the problems that corrosion resistance of common rubber sealing materials is weak; and after long term use, the surface of the common rubber sealing materials ages easily, the mechanical properties of the common rubber sealing materials are decreased so that the sealing ability of the common rubber sealing materials is decreased accordingly.