Abstract: In this paper, the performance test of tensile strength of Polyimide and Vectran envelope materials after ozone aging is introduced, and the change rates of tensile strength of the two types of envelope materials are analyzed and compared. The relevant test data show that the polyimide envelope material has better ozone aging resistance. In the selection of envelope material for stratospheric airships, polyimide can be widely used for envelope materials of stratospheric airships because of its stable chemical properties.