High voltage circuit breaker is an important equipment in power grid. The healthy state of circuit breaker is of great significance to ensure the safe and reliable operation of power grid. Based on the acquisition of the health status of circuit breaker components

this paper presents an evaluation method of the overall health degree of circuit breaker based on the improved hidden Markov model. The short-term and long-term health of circuit breaker is predicted on time scale

then the intelligent quantitative grading strategy of maintenance work is put forward. The effectiveness of the method is verified by a practical example.