Abstract: The mechanical property of polypyromellitimide film in electron radiation was studied in Φ800 mm combined space radiation test facility in Beijing Institute of Space Environment Engineering（BISEE），and the influence of flux，fluence and temperature of electron radiation on the mechanical property of the film was studied.The following results can be obtained：the tensile force，tensile strength and rupture elongation of polyimide film decrease firstly and then exponential increase with the increase of electron radiation fluencies.At the same electron radiation fluence，the tensile force and tensile strength of polyimide film increase with the increase of electron radiation flux，but the rupture elongation decrease firstly and then increase with the electron flux.The mechanical properties of polyimide film increase with the increase of test temperature.