Abstract: Fuze irradiation experiment data analysis of high power microwave (HPM) electromagnetic pulse is an important problem of HPM electromagnetic effect. The high-dimensional complexity of HPM electromagnetic effect data is the main difficulty of data analysis. HPM electromagnetic effect data on a certain type of radio fuze is analyzed by the fuzzy C mean (FCM)clustering algorithm method, through the design of FCM clustering algorithm. The algorithm processes need several times of iterative computation with the principle of inner class similarity and inter class differences .The optimal classification and the best cluster center of pulse width, peak power, power density of the high power microwave are both obtained. Experimental results show that the optimal clustering center of a fuze under HPM, namely the best interference threshold causing fuze failure can be obtained and the FCM algorithm is validity.