Under the new normal state, the PPP project will play a more and more important role in the social and economic development of China. To improve the performance of PPP project management, it is necessary to implement integrated project governances. Firstly, according to the index system of two kinds of PPP projects governances (Contract Governance and Relationship Governance) and PPP project management performance determined by theoretical analysis, the DDX project is selected as the analysis object. After identifying the case, this paper explains the basic information and preliminary work of the case. Then, the three contents of contract governance, relationship governance and project performance are analyzed comprehensively. Case studies show that all of these two governance modes have positive effects on project management performance. However, due to the lack of information in the case, the validity of the conclusion also needs to be verified again.