The problems of abnormal heating of composite insulator rods should not be ignored during actual operation. The electro-thermal-mechanical stresses will significantly accelerate the aging process of rods and may develop into fracture failure. We carried out electro-thermal-mechanical multi-field aging experiments on composite insulator rods. Based on the microscopic hole charge energy

the multi-field aging life model was proposed. The modified rod with high thermal conductivity was prepared to effectively improve the aging resistance. The results show that the strain of the hole will be continuously expanded. A life model based on the microscopic hole charge energy is established

and the maximum hole charge energy (0.21 eV) at the end of life is defined. The mapping relationship between the service life of artificially accelerated mechanical-electro-thermal aging rod sample and the actual aging rod sample was established by comparing the hole charge energy of the composite insulator rod sample with that of the actual operating sample. Finally

the combined modification of multi-wall carbon nanotubes and boron nitride nanosheets can effectively improve the thermal management ability of rods. The aging fracture time of modified rod is about 30% longer than that of conventional rods. The above research results can provide theoretical reference for fracture failure prediction and life evaluation

as well as the modification methods for improving the aging resistance of composite insulators.