Abstract: This paper focuses on the lifetime characteristics of pulse capacitors applied in millisecond pulse discharge through the establishment of the repetition-frequency lifetime test platform. The pulsed power charger adopts the mode of constant current charging and the output power is 30 kW with the voltage range between 0 kV and 12 kV. The switch of the pulse discharge circuit is a thyristor whose repetition frequency is up to 100 Hz. The discharge waveform can be adjusted by load resistance and load inductance. The effect of the charging time, hold time, intervals and repetition frequency on the lifetime characteristic of pulse capacitors can be sufficiently studied. Meanwhile, failure mechanisms of pulse capacitors in specific working conditions can be investigated.