Abstract: The sealing of GIS has been an important aspect in the field of gas insulated transmission and transformation equipment technology. Current methods to diagnose aging and predict lifetime of GIS seal rings do not meet the reliability requirements of the key components in the contemporary power industry. There is an urgent need to review the current research in this field with a new framework, so to inspire new research ideas. This article analyzed the level, distribution, and effects of aging factors including compression, thermal, and chemistry. On this basis, we reviewed the development of accelerated aging methods. This effort was starting from conventional thermal aging on standard specimens, and all the way down to the multi-factor aging on complete O-rings in specially designed device filled with SF₆ gas. Then as an important aspect, the mechanical properties, physico-chemical characteristics, and gas leakage characteristics of aged GIS seal rings were reviewed. More attentions need to be paid on the significant heterogeneous aging characteristics of GIS seal rings under the effect of atmospheric/insulating gas media. Finally, we reviewed the lifetime prediction models and failure criteria for vulcanized rubber seal rings. This article can provide a fundamental reference for academic and engineering research.