Epoxy resin has an important role in protection of electrical components, and the method of introducing naphthalene is also an important modification method of epoxy resin. In this paper, dihydroxynaphthalene epoxy resin was prepared from 2,7-DON and ECH, and then mixed with curing agent DDS. The curing kinetics and hydroxyl content in different curing time and the molecular chain spacing in different curing time were test by DSC, FTIR and XRD respectively, and then the optimal curing process was obtained.