Abstract: Sterilization of spacecraft hardware on Earth is a critical step in deep space planetary protection missions. This paper verified the efficacy of two sterilization methods, dry heat sterilization and hydrogen peroxide low-temperature plasma sterilization, on polyimide films commonly used in spacecraft construction. Specifically, the post-sterilization mechanical and electrical properties, and the applicability in sterilized conditions, of PI100 and GSI025 polyimide films were evaluated. The results indicate that both sterilization methods have no significant effect on the tensile strength and elongation at break of PI100. Notably, the breakdown strength of PI100 following 135 ℃ dry heat sterilization is significantly higher than that of the untreated control group. Additionally, the surface resistivity of GSI025 remains largely unaffected by either sterilization method. This study provides a valuable reference for the selection of appropriate sterilization methods for polyimide films intended for use in spacecraft.