Abstract: 　　
　　Green retrofit of existing buildings is a key move to achieve the goal of "carbon neutrality and carbon peak" in the construction field and to promote the strategy of high-quality development, and the scientific and effective synergy of decision-making bodies contributes to the efficient implementation of the project and the healthy development of the market. We start from the perspective of market governance, compare the related theoretical research dynamics at home and abroad, analyse the complexity and specificity of the subject decision-making synergy, demonstrate the necessity and significance of the research on the mechanism and path optimization of the subject decision-making synergy, plan and design the research objectives and contents, elaborate the research ideas, formulate the research technical route, and construct the research framework, so as to enrich the decision-making theory of the subject's behaviour in the green renovation of the existing buildings, and provide a theoretical basis and practical basis for the related policies of green renovation of the existing buildings. It provides theoretical basis and practical direction for relevant policies of green transformation of existing buildings, and promotes the long-term development of green transformation of existing buildings in China.