Focused on the institutional transition and scheme evolution of mega infrastructure investment and finance, the phases of relevant institution were analyzed. A governmentmarket dual evolutionary game model on mega infrastructure investment and finance was built. Then, the decisionmaking level of the government, investment willingness and investment amount, the yield and risk of mega infrastructure investment on the evolutionary stable strategy of both agents and their mixed strategy combining system simulation technology were studied. Finally, the feedback mechanism between policy, institution, decisionmaking level of government and investment willingness were discovered. The two parameters together with the investment ability of the government, the yield and risk of mega infrastructure investment have a great impact on the investment and finance scheme. The evolution path is determined by the institution transition route.