At present, the maintenance of flexible DC converter valves suffers from the problems of frequent temporary maintenance, insufficient or excessive maintenance. In particular, there is a lack of relevant research on the aging mechanism of IGBTs to support it. This article provides a comprehensive review of the research on the aging mechanism of press-pack IGBTs. The aging mechanism is divided into fretting wear aging, gate oxide aging, boundary warping aging, short-circuit aging and other aging, The corresponding aging mechanisms, experimental tests, etc. are carried out. Finally, the research on the aging of IGBTs for flexible DC converter valve maintenance is prospected, and the future looks promising.