The invention discloses an epoxy resin composite material and a preparation method thereof. The preparation method of the epoxy resin composite material comprises the following steps: firstly, preparing a tungsten phosphorus peroxide heteropolyacid phase transfer catalyst; then preparing epoxidized SBS (Styrene Butadiene Styrene); raising the temperature and curing; finally, obtaining the epoxy resin composite material. According to the epoxy resin composite material, as 5 percent of the epoxidized SBS is added to modify epoxy resin, the toughness of the epoxy resin composite material can be effectively improved by 25 percent; the modulus, strength and transparency are not influenced. The epoxidized SBS disclosed by the invention is self-assembled to form a 20 to 50nm spherical micelle andthe spherical micelle is uniformly dispersed into an epoxy resin system; the epoxidized SBS has spontaneity and does not need very strong mechanical energy.