Abstract: The theoretical formula of gas permeation acceleration factor was derived for barrier materials under different gas temperature and pressure. The theoretical calculation results are consistent with the experimental results (in the literature). The permeability of various gases，including water vapor, oxygen and carbon dioxide, through polyethylene terephthalate (PET) plastic and epoxy resin, was measured by mass spectrometry under accelerated conditions. At normal temperature and pressure, the gas permeabilities of PET plastic film with a thickness of 0.155 mm are 1.110-2 g/(m2d), 1.610-4 cm3/(m2d), 810-4 cm3/(m2d), and the gas permeabilities of epoxy resin film with a thickness of 0.065 mm are 1.710-2 g/(m2d), 3.510-5 cm3/(m2d), 5.510-5 cm3/(m2d).