In order to study the effect of micron silica on the surface resistance of epoxy insulating materials and improve the resistance of epoxy resin micron composites, three kinds of epoxy resin composites doped with different micron silica particles were prepared. By using the ASTM D2132-62T test method, the resistance of epoxy micron composites was evaluated by recording the time of electrical mark failure. The hydrophobicity of the sample was studied by static contact angle measurement, and the electrical and mechanical properties of the sample were tested. The results show that with the increase of the doping content of micron silica particles, the resistance to electrical marks and hydrophobicity of the samples become better, The dielectric constant of the sample decreases first and then increases, the dielectric loss is constant, the volume resistance decreases first and then increases, but the dielectric strength increases first and then decreases, and the difference of electrical properties of different samples is small. both the bending strength and the tensile strength are slightly increased, and the impact strength decreases first and then increases. the comprehensive test of the electrical and mechanical properties of the specimen increases the bending strength and tensile strength of the specimen, appropriately reduces the dielectric constant and volume resistivity, and increases the dielectric strength, which can make the resistance of epoxy micron composites better.