Abstract: C₆F₁₂O gas mixture has excellent insulation properties, thus it is expected to be used as an insulating medium in medium and low-voltage electrical switchgear. In order to ensure the long-term safe and stable operation of equipment, the compatibility between C₆F₁₂O and sealing rubber materials is one of the important factors that cannot be ignored. In this paper, the compatibility between C₆F₁₂O/N₂ gas mixture and common sealing rubbers (EPDM, NBR and FKM) at different temperatures is studied. The composition of the mixed gas is analyzed by gas chromatography mass spectrometry, and the properties of the rubber materials are detected by scanning electron microscope, X-ray photoelectron spectroscopy, and tensile stress machine. At the same time, a simulation model of C₆F₁₂O and rubber molecular chain is built, and the diffusion and adsorption of C₆F₁₂O in rubber materials are calculated and analyzed from the molecular level. The experimental results show that, with the increase of experimental temperature, C₆F₁₂O/N₂ gas mixture reacts with three rubber materials to produce C₃F₆, C₃F₇H, and CS₂ gas by-products with FKM. At the same time, dense folds may appear on the surface of EPDM, while a large number of crystal particles are precipitated on the surface of NBR, and a large amount of F element is accumulated on the rubber surface. After the experiment, the mechanical properties of EPDM and NBR are significantly reduced. The surface structure and mechanical properties of FKM are negligibly affected by the C₆F₁₂O/N₂ gas mixture. The calculated results are also in agreement with the experimental results. Increasing the temperature can facilitate the adsorption between C₆F₁₂O and rubber. At 90 ℃, the diffusion and adsorption energy between C₆F₁₂O and EPDM are the highest (8.912×10^–11 m/s² and 317.436 kJ/mol), respectively, and the adsorption energy between C₆F₁₂O and FKM is the lowest. Therefore, the comprehensive analysis of the experimental and theoretical calculation results shows that the compatibility between C₆F₁₂O/N₂ and FKM is better. The research results of this paper can provide important guidance for the application of C₆F₁₂O/N₂ gas mixture in engineering.