The present invention makes it possible to provide a method for producing a polyfunctional sulfur-containing epoxy compound, the method being characterized in that a polyfunctional thiol is reacted with an epihalohydrin in the presence of a reducing agent to form a polyfunctional sulfur-containing halohydrin, which is then reacted with a basic compound. The reducing agent is preferably at least one selected from the group consisting of sodium borohydride, lithium borohydride, lithium aluminum hydride, diisobutylaluminum hydride, and hydrazine.