Abstract: Taking the cross-linked ethylene tetrafluoroethylene copolymer (X-ETFE) cable used outside the spacecraft as the test object, the X-ETFE cable was irradiated with 8000 equivalent solar hours (ESH) vacuum ultraviolet (VUV) with a 5-fold acceleration factor. The electrical properties of the X-ETFE cable were analyzed through the limit voltage resistance and insulation material resistance tests. The molecular structure and micro morphology of the X-ETFE material were characterized by FTIR and SEM, The effects of different VUV irradiation time on X-ETFE cable have been studied.. The experimental results show that with the increase of VUV irradiation time, carbon accumulates on the material surface and darkens, and the appearance color of the cable gradually changes to dark brown; The ultimate withstand voltage and insulation resistance of X-ETFE cable show an overall downward trend, but the overall electrical performance level has no substantial change; The absorption peak of X-ETFE material at 1628 cm⁻¹ gradually increases, indicating that the −C=C− free group in the molecular chain of X-ETFE material increases with irradiation time, resulting in microcracks on the surface of the material.