ABSTRACT: Although traditional outdoor insulation materials (such as ceramic and glass) have the advantages of stable chemical properties and excellent insulation performance, they are difficult to deal with the occurrence of pollution flashover in the wet and dirty environment of outdoor operation. The application of organic outdoor insulation materials (such as silicone rubber) has become a solution to this problem. Their good hydrophobicity enable them to maintain a long time of normal operation in dirty areas. However, due to long-term complex outdoor working conditions, silicone rubber will also be aging under the impacts of a variety of factors, resulting in poor performance or even unable to use. Up to now, the research of improving and strengthening the performance of organic outdoor insulation materials is still a research hotspot. This paper reviews the researches on the aging mechanisms of silicone rubber insulation materials in recent years and the achievements of performance improvement work, and summarizes the effects of various improvement methods on its performance.