In the early years, insulators were mostly used for telegraph poles. With the development of science and technology, a lot of disk-shaped insulators are hung on one end of the high-voltage wire connection tower. It is used to increase the creepage distance. It is usually made of glass or ceramics. , It's called an insulator. Insulators play two basic roles in overhead transmission lines, namely supporting wires and preventing current from returning to the ground. 

These two roles must be guaranteed. Insulators should not fail due to various electromechanical stresses caused by changes in the environment and electrical load conditions. Otherwise, the insulator will not have a major effect and will damage the use and operating life of the entire line.