Insulator is a special insulation control, which can play an important role in overhead transmission lines. In the early years, insulators were mostly used for poles, and gradually developed into high-voltage wire connection tower with many disc-shaped insulators hanging at one end. It is to increase the creepage distance, usually made of glass or ceramics, called insulators.

Insulator plays two basic roles in overhead transmission line, namely supporting conductor and preventing current from returning to ground. These two roles must be guaranteed. Insulator should not fail due to various mechanical and electrical stresses caused by changes in environment and electrical load conditions. Otherwise, insulator will not play a significant role and will damage the service life and operation life of the whole line.