Abstract: In order to accurately evaluate the state of the energy storage spring and ensure the reliable operation of the circuit breaker,this article proposes a circuit breaker fault diagnosis method based on the energy storage spring pressure signal.Firstly,a dedicated fixture was designed to collect pressure signals,and a detailed analysis of the stress process was conducted.Then,the pressure impulse,kurtosis,effective value,peak factor,and margin index were extracted as feature parameters.Finally,the Fireworks Algorithm（FWA） was used to optimize the kernel parameters and penalty factors of the Support Vector Machine（SVM）,and the sample data was fed into the SVM for state identification.The experimental results show that the accuracy of using pressure signals for fault diagnosis reached 96.6%,which has broad application value.