Charging characteristics of polymer irradiated by multi-energetic electrons is a basis to study and prevent electrostatic discharge in space radiation environment. The polymer irradiated by multi-energetic electrons is modeled and simulated. The space charge distribution, surface potential, space potential, surface potential and maximum field strength under the condition of sample parameters are obtained. The results show that because of electron drift and diffusion, electrons can transit through the electron scattering region, forming negative space charges. Some electrons can flow to the substrate of polymer. In the equilibrium state, the surface potential of the film negatively charged decreases with film thickness and trap density increasing, and it increases with electron mobility and relative permittivity increasing. The maximum field strength increases with film thickness and trap density increasing, and it decreases with electron mobility and relative permittivity increasing. The high-energy electrons section of multi-energetic electrons will shorten the equilibrium of charging process.