In order to avoid unnecessary potential renegotiations in transport infrastructure PPP project, reduce the management cost and improve the efficiency, the renegotiation trigger point identification model based on casebased reasoning (CBR) technology is proposed. Firstly, the rough set theory is used to simplify the initial case feature attributes, and the entropy weight method and analytic hierarchy process are used to optimize the feature weights of each case. And then the most likely occurred renegotiation trigger point in the proposed project is identified by general similarity search of the case and source cases similar to PPP project. Finally, the rationality and effectiveness of the model are verified by case study of the PPP project of Shenzhen Wutongshan Tunnel, and corresponding preventive measures are proposed.