Abstract: To acquire spontaneous discharging data of the polymers in spacecraft under energetic electrons with continuous spectrum and investigate the discharging characteristics of the polymers, ⁹⁰Sr β source is utilized to irradiate Polytetrafluoroethylene(PTFE) samples and the spontaneous discharging pulse data are recorded. By statistic analysis of the data, it is shown that the irradiation duration, the electron flux and the temperature all can affect the discharging risk and pulse characteristics. Continuous irradiation under energetic electrons may reduce the discharging threshold of the PTFE. After several days of irradiation, the discharging tends to be more frequent with a lower intensity. When the electron flux gets higher, the discharging interval gets shorter and "big" discharging events are more likely to happen. When the temperature goes down, the dielectrics become less conductive with higher charging potential and greater discharging risk. Once the discharging happens, the average magnitude of pulses gets larger than that under a higher temperature condition.