Abstract: With power equipment gradually developing towards high-power and miniaturization, equipment heating is becoming increasingly severe, which will not only greatly shorten the life of the medium, but also more likely to induce DC flashover. In order to solve the above problems, a composite with oriented Al₂O₃ sheets is used to reasonably design the electrode position to make the heat dissipation between the electrodes slower and faster in the vertical electrode direction, so as to effectively suppress the DC surface flashover and efficiently heat dissipation. For the surface flashover of epoxy resin at HV electrode heating, the influence of the thermal conductivity of the Al₂O₃-oriented composite on its temperature distribution is studied, and the influence of temperature distribution on the surface electric field distribution of the Al₂O₃-oriented composite is analyzed. The research shows that when the orientation direction of the Al₂O₃ sheets is perpendicular to the surface flashover path, the conductor heat transfer to the ground electrode can be inhibited, thereby reducing the electric field distortion at the three nodes of the anode and inhibiting the DC flashover along the surface.