In the power distribution, the high-voltage switchgear circuit breaker is a very important component, which is used to protect and control the power system, which is directly related to the safe operation of the entire power grid. The continuous improvement of the comprehensive automation level of substations also requires that the reliability of high-voltage circuit breakers should be improved. High-voltage circuit breakers will have many power outages, and the loss is far greater than the cost of the equipment itself. Therefore, the state monitoring of the circuit breaker should be strengthened. Be able to understand its operating conditions, grasp its operating characteristics and changing trends, and prevent potential failures. In order to ensure the reliable operation of the system, preventive measures or maintenance should be taken immediately. The online monitoring technology of high-voltage circuit breakers provides the basis for the equipment's condition maintenance mechanism, and creates favorable conditions for the transition from planned maintenance to condition maintenance, which is of great significance.