Circuit breaker is a switch device that can turn on, bear and break normal current in circuit, as well as turn on, bear (within stipulated time close) and break the abnormal current. The application of counters in circuit breaker is analyzed according to the current usage of circuit breaker in the substation. Counters can display and accumulate closing frequency of circuit breakers, and the quality of counter will not immediately affect the normal operation of the circuit breaker. Counters can effectively evaluate the lifetime of circuit breakers and judge its operation condition, and provide basic data foundation for the construction of smart substation.