Parylene-C film was mainly used for three-proofings of power brushes to ensure the stable transmission of electric power. The thickness， thermal ability， insulation performance，adhesive force on beryllium bronze and space irradiation resistance of Parylene-C film （specifications：17 and 27 μm） were studied.The results show that the thickness error of Parylene-C film made by vaccum gas phase deposition can be controlled within 2 μm；the adhesion of Parylene-C on beryllium-bronze is 1 grade； thermal decomposition temperature is 453 ℃；the breakdown voltage of 17 and 27 μm Parylene-C film are 3.65 and 5.27 kV， respectively； the appearance is intact and adhesive force， thermal ability，insulation performance of Parylene-C film can meet the requirements of engineering application after 2.5×10¹⁵ p/cm² proton irradiation. However，serious cracks and peelings occurr on Parylene-C film after 2.5×10 ¹⁶ e/cm² electron irradiation.At last， the thermal properties and FT-IR of Parylene-C film are further studied before and after electron irradiation，by which， the failure mechanism is analyzed and the electron irradiation upper limit 1×10¹⁴ e/cm² is obtained.