The self-designed adjustable ultraviolet aging experimental box was used for the accelerated aging experiments (0–1000 h) of HTV silicone rubber from two factories, A and B, with the radiation wavelength ranging from 320–750 nm. The tensile test, hardness test, and the measurements of volume resistivity, surface resistivity, disruptive strength, and hydrophobicity were used to evaluate the mechanical and electrical properties of HTV silicone rubber and its change mechanism is further investigated by Fourier transform infrared spectroscopy (FTIR). The results showed that tensile strength of sample A and B dropped from 6.4 MPa to 4.6 Mpa, and from 5.1 MPa to 4.6 MPa, accounting for 28% and 9% respectively; their longation at break dropped from 156% to 76%, and from 247% to 148%, accounting for 51.3% and 40.1% separately; hardness increased 1−2 degrees. In addition, volume and surface resistivity and disruptive strength suffered a drop of various degrees, and hydrophobicity decreased by 1−2 degrees level. After ultraviolet radiation, the mechanical properties and electrical properties of A and B samples are reduced.Cited