Abstract: Cross-linked polyethylene (XLPE) has been widely adopted as the primary insulating material for power cables due to its excellent dielectric properties and physicochemical stability. However, during actual cable operation, under the combined influence of various external stresses such as electric fields and temperature, the insulating material inevitably undergoes processes including thermal aging and electrical aging. This leads to the degradation of its electrical and mechanical properties, which not only shortens the cable's service life but also poses a serious threat to the safe and stable operation of the power system. This paper systematically elaborates on the aging mechanisms of XLPE cables under thermal aging, electrical aging, and long-term service conditions. It reviews the influence patterns of different aging modes on their microstructure, space charge transport behavior, and dielectric properties, and explores the intrinsic relationship between charge transport characteristics and dielectric performance. The research findings can provide theoretical foundations and experimental support for the design optimization, condition assessment, and operational maintenance of XLPE cable insulation.