The invention discloses a tetrafluoroethylene-propylene rubber/silicone rubber/chloroprene rubber composite sealing pad and a preparation method thereof. The tetrafluoroethylene-propylene rubber/silicone rubber/chloroprene rubber composite sealing pad is prepared from the following raw materials: tetrafluoroethylene-propylene rubber, silicone rubber, chloroprene rubber, magnesium methacrylate, 2, 4-dichloro-benzoyl peroxide, N, N'-m-phenylene bismaleimide, C5 petroleum resin, gas phase white carbon black, modified fluorite powder, nano-silicon nitride and the like. The tetrafluoroethylene-propylene rubber/silicone rubber/chloroprene rubber composite sealing pad disclosed by the invention selects the tetrafluoroethylene-propylene rubber with unique resistance to compression permanent deformation as a main raw material and takes the silicone rubber with excellent heat resistance, cold resistance, ozone resistance and atmospheric ageing resistance and the chloroprene rubber with excellent oil resistance and chemical corrosion resistance as auxiliary materials, the rubber sealing pad prepared by blending has the advantages of good sealing effect, good corrosion resistance, high cream content, capability of working for a long time in acid, base, oil and other media, small changes in volume and hardness and effect of being less prone to cracking, as well as excellent compression rebound resilience, high temperature resistance, cold resistance, aging resistance and the like, and the rubber sealing pad is durable.