With the development of power electronic devices towards high frequency, large power and lightweight, high frequency becomes one of the important reasons of the high frequency transformers failures. In this paper, a high-frequency electrical aging experiment system is built, and the surface potential attenuation method is used to measure the surface charge accumulation and attenuation characteristics of oil paper insulation with different aging degrees. The results show that as the applied frequency increases, the amount of charge accumulated on the surface of the insulating paper decreases, and the charge attenuation rate increases first and then decreases. After high-frequency aging, the surface charge accumulation and attenuation rate of oil-paper insulation decreases with the increase of aging degree. When the frequency is lower than 5 kHz, the high-frequency heating effect on the surface of the insulating paper plays a leading role, and when the frequency is higher than 5 kHz, the charge dissipation time caused by the high frequency plays a leading role, causing the surface charge attenuation rate to increase first and then decrease. As the degree of high-frequency electrical aging increases, the probability of initial electron generation of oil-paper insulation decreases. Understanding the characteristics of surface charge accumulation and dissipation provides a theoretical basis for revealing the electrical aging mechanism of oil-paper insulation under high frequency.