Epoxy resin nanocomposites are widely used in the field of electrical insulation due to their excellent electrical, thermal and mechanical properties. Hexagonal boron nitride (hBN) is often used as a filler for epoxy resin modification due to its unique structure and various excellent properties. In this paper, boron nitride was selected as a filler to study the insulating properties of boron nitride epoxy composite resin under AC. To this end, different contents of hexagonal boron nitride epoxy resin composites were prepared, and AC along surface flashover and AC breakdown experiments were carried out for epoxy resin composites with different contents of hexagonal boron nitride at different temperatures, respectively. The results show that compared with the pure epoxy resin, the doping of hexagonal boron nitride filler affects the insulating property of the epoxy resin, and the AC along-surface flashover voltage and AC breakdown voltage are significantly changed with different hBN contents; the insulating property of the epoxy composite resin is the best when the hBN content is 20 wt%, and the AC along-surface flashover voltage and the AC breakdown voltage reach the maximum.