Surge Protective Device is a protection device, referred to as SPD, it plays an important role in the protection of electronic equipment .It makes the transient overvoltage which put into the electronic equipment limit in the acceptable range and withstands the impact of the shock current. It protects electronic equipment from these damages. However, due to the accumulation of longterm working voltage or the impact of shortterm shock current, SPD will inevitably lead to aging, if not found in time, electronic equipments will have serious consequences. This paper summarizes the domestic and foreign scholars on the aging mechanism of SPD and its research progress, the detection of SPD aging degree and the method of improving the stability of SPD.