The circuit breaker is a fundamental component of high-voltage switchgear. Under long-term service conditions, the mechanical performance of the switchgear circuit breaker is crucial for ensuring the safe and reliable operation of the equipment. This article selects the travel time curve during the opening and closing processes as a parameter to characterize the mechanical performance of the switchgear circuit breaker. By moving and smoothing the travel time curve signal and applying the principles of difference and maximum solution, effective extraction of the characteristic quantities of the circuit breaker travel time curve is achieved. The study investigates the variation of various characteristic quantities, including overtravel, opening distance, opening and closing time, speed, bounce time, and overshoot, in relation to the number of times the circuit breaker is opened and closed. The aim of this study is to elucidate the degradation patterns of the performance of switchgear circuit breakers and to provide experimental support for on-site operation and maintenance personnel, enabling them to effectively monitor the mechanical performance of circuit breakers.