Deep charging & discharging experiment on polyimide films is  performed using DECDIS (Satellite Deep Charging & Discharging  Simulator).Deep charging processes on samples of various thicknesses  under different irradiation conditions are compared. The surface voltage  of the polyimide film can reach up to 8000 volts. The experiment  initially reveals the deep charging rules of polymer materials, which  offers a reference for the study and mitigation of deep charging &　discharging effects.