The invention discloses a preparation process of high purity electronic grade hydrogenated bisphenol A epoxy resin. The preparation process comprises the steps: enabling glycidol, which is taken as a raw material, to react with pyridine and methanesulfonyl chloride; after the reaction is completed, washing, layering, filtering and concentrating, and rectifying to obtain a main fraction I; adding the main fraction I into a solution of hydrogenated bisphenol and sodium hydride for reaction while stirring; after the reaction is completed, washing, layering, filtering and concentrating to obtain high purity electronic grade hydrogenated bisphenol A epoxy resin having a total halogen content of not more than 1000 ppm. According to the preparation process disclosed by the invention, no epichlorohydrin is used as a raw material in a synthesis process, epichlorohydrin is replaced with a reaction product of glycidol and methanesulfonyl chloride, and finally the high purity Hydrogenated bisphenol A epoxy resin having a low total halogen content is obtained.