Abstract: In order to solve the problems of spalling, secondary cracking and electrical failure of insulation parts when existing insulation repair materials fluctuate in a wide range of temperatures, a variety of nanoparticle-filled silicone rubber/epoxy resin composite repair coatings were developed in this paper, and the adhesive strength, electrical properties and microstructure of the repair coatings were compared and analyzed before and after cold and hot shock cycles. The results show that the thermal shock can cause the main chain break of repair coatings, produce low molecular products and oxidation free groups, increase the relative dielectric constant and dielectric loss of the coatings, and decrease the breakdown field strength. The functional nano-masterbatch can improve the interfacial bonding energy and hinder the polymer molecules of the tension and torsion, so that the paint has a relatively stable chemical structure. Therefore, the extension of the local deterioration channel in the matrix can be prevented under the cold and heat shock, effectively restraining the deterioration of the electrical resistance of the repair coatings. When the content of glass fiber, nano-ZnO and nano-SiO₂ is 16%, the electrical properties of the coating is good. The silicone rubber epoxy composite repair coating has the advantages of short curing time, no swelling and good adhesion, which makes it possible to quickly repair the insulation of equipment.