Under the condition of frequent overvoltage of electrified railway, the arrester of EMU will accelerate aging and cause system failure. Aiming at this problem, the aging characteristics of arrester under frequent overvoltage conditions are studied in this paper. The aging test platform of arrester under high frequency overvoltage is built. The influence 1mA aging time and overvoltage frequency on the surface elements of lightning arrester before and after aging is analyzed. The effects of frequent overvoltage on the aging of the arrestor are given. It is shown that the aging resistance of lightning arrestor is affected by the applied voltage frequency, the increase of voltage applied time and the charge rate, the 1mA DC reference voltage will decrease after aging, and the leakage current will increase at 0.75 times DC reference voltage. The research provides theoretical basis and data support for the development of high-capacity and high-reliability arrestors for electrified railways.