Abstract: To deeply investigate the influence of corona aging on surface flashover and surface charge of silicone rubber, Silicone rubber was aged by multi-needle-plate electrodes at different aging time. By measuring the surface charge of aged silicone rubber at different aging time and from zero voltage to flashover, the change of surface charge and surface flashover of aged silicone rubber were studied. At last, in order to investigate the influence of the trap characteristics on the surface charge of silicone rubber, thermal stimulation current（TSC）, scanning electron microscopy（SEM） and Fourier transform infrared spectroscopy（FTIR） tests were used to observe the change of micro electrical properties, physical and chemical defects of the samples at different aging time. According to the tests results, with the increase of corona aging time, the trap level of silicone rubber goes deep, trap charge increases and the capacity of silicone to capture charge gets enhanced which causes the raise of surface charge. It can also be known that with the increase of voltage level, the maximum of surface charge gradually approaches the nearest area between two electrodes until partial discharge gets through the two electrodes and results in surface flashover. In conclusion, with the increase of corona aging time, the capacity of silicone rubber to catch charge gets enhanced which causes a stronger partial discharge is the reason for the decrease of flashover voltage.