In　recent　years,　the　continuing　happened　engineer　disasters　and　accidents　cause　enormous　economic　losses　and　negative　social　influence.　As　a　result,　the　risk　control　problem　of　major　public　construction　projects　was　paid　much　attention.　The　public　construction　projects　are　relate　to　the　public　life　quality　and　the　common　security　benefits,　so　risks　become　the　most　important　control　elements.　Effective　risk　control　should　be　based　on　the　reasonable　risk　management　mechanism.　However　so　profound　influence　was　caused　by　the　traditional　ideas　and　so　many　multiple　benefits　were　interlaced　in　the　open　life-cycle　processes　of　major　public　construction　projects.　These　induced　some　construct　stages　and　participants　become　risk　control　blind　spots.　Thereby　the　highefficient　risk　management　system　should　get　the　help　from　the　thirdparty,　which　is　independent　of　any　projects　participants,　to　intervene　in　major　public　construction　projects＇　life-cycle　risk　management.　The　third-party　is　which　called　forensic　engineering.　In　this　paper　the　idea　of　life-cycle　risk　management　was　put　forward　based　on　the　engineering　operation　processes　in　all　life-cycle,　the　stages　risks　and　duties　of　modern　engineers　were　analyzed,　the　conception　of　forensic　engineering　was　introduced,　and　how　the　forensic　perfect　to　the　risk　management　mechanism　was　explained.　©2009　IEEE.