The invention relates to a cardanol epoxy resin, belonging to epoxy resin materials. The process comprises the following steps of: 1, adding bisphenol A, cardanol and epichlorohydrin in proportion into a reaction kettle; 2, heating and adding solid sodium hydroxide; 3, dropwise adding a sodium hydroxide solution, discharging water generated by reaction and the epichlorohydrin out of the reaction kettle by azeotropy, and returning the epichlorohydrin into the reaction kettle after condensing and decomposing for continuing the reaction; 4, after the reaction, distilling off water and most of the epichlorohydrin from the material in the reaction kettle, and removing the residual epichlorohydrin by a film evaporator to obtain crude resin; 5, adding an organic solvent and soft water into a refining kettle, dropwise adding the residual sodium hydroxide solution, wherein the organic solvent is toluene or methyl isobutyl ketone; and 6, removing the organic solvent from the refined resin solution by a film evaporator to obtain the product. The used cardanol is environment-friendly, energy-saving and pollution-free, and the cardanol epoxy resin obviously improves the brittleness, toughness and weatherability of the cured resin.