Abstract: Thyristor has the advantages of good control characteristics, long life time, small size, low noise, etc., and it is an important device for high-power pulsed power supplies. However, when a thyristor is used under high voltage, high current, and repetitive frequency working conditions, the thyristor may not be turned off within a certain time, causing the pulse power supply to fail. To improve the working ability of the thyristor under repetitive frequency, this paper studies the turn-off process of the pulse power thyristor component. Based on the turn-off principle and experimental analysis of the thyristor, it is found that under the same conditions, increasing the current peak value has little effect on the reverse recovery characteristics of the thyristor, and the relationship is got between reverse recovery time, reverse recovery charge and di/dt of the thyristor. The reverse recovery current waveform of the thyristor is fitted according to the experimental data, and the current exponential function model is modified to better fit the reverse recovery current.