Discussion　on　optimized　cost　compensation　and　relevant　incentives　system　has　been　carried　out　in　this　paper　aiming　at　promoting　private　investment　in　public　projects.　Parameters　have　been　optimized　based　on　contracting　and　incentive　theory,　leading　to　the　conclusion　that　dissymmetric　information　may　weaken　the　strength　and　effect　of　incentive　contracting,　while　the　government　profit　gaining　will　debase　the　stimulation　in　turning　fixed　prices　contracting　to　cost-price　contracting.