For High altitude airship (HAA) with long time affected by space harsh environment, due to the occurrence of natural light radiation aging physical and mechanical properties, fiber-reinforced airship envelope material results in degradation of the mechanical load performance, even causing damage to the balloon airship. Based on the ground aging simulation of the airship envelope material under the natural light, the morphology of airship envelope material in the natural aging process can be observed and the specimen comparison test is carried on for its fracture strength and breaking elongation to qualify its mechanical properties. The specimens with the axial angle of 0°and 90°were respectively tested to get its mechanical properties and the comparative analysis on degradation of fracture strength and breaking elongation before and after its 720h aging is developed too. The test results shows that the mechanical properties of different specimens decrease, wherein the maximum degradation is 0° specimens and that of 90°specimens t is not very significant weakening. Natural aging characteristics of airship envelope material provide support for the design and improvement of anti-aging properties of the airship envelope material.