The　urban　rail　transit　system　is　widely　adopted　in　big　cities　for　its　large　transit　capacity,　fast　speed,　low　power　consumption,　and　comfortable　riding　experience.　But　recently　frequent　metro　accidents　appear　and　the　subsequent　social　impact　is　very　bad,　which　remind　us　of　the　risk　in　the　rail　transit　system.　Therefore,　this　paper　analyzes　the　risk　factors　in　rail　transit　project,　divides　them　into　different　phases,　and　then　specifies　the　risk　in　different　phases.　Then,　an　AHP-based　fuzzy　comprehensive　evaluation　model　is　developed　for　the　urban　rail　transit　system　based　on　the　identified　risk　factors.