The risk sharing of PPP projects in underground utility tunnel is complex. Hence, a risk sharing method based on grey correlation and D-S evidence theory is proposed. Firstly, the key factors affecting PPP projects are extracted by case analysis method, and the risk sharing index system for PPP projects in utility tunnel is constructed based on the specific characteristics of the utility project. Secondly, a multi-level risk sharing index system is constructed by comprehensively considering the risk preferences of all participants. Thirdly, the correlation between indices is analyzed by means of grey correlation method, a more accurate evidence composition formula is given, and a comprehensive risk sharing model is established based on previous evidence theory and the analysis on the influence of non-key factors. Fourthly, the model is applied to the underground utility tunnel PPP project in Jinan High-tech Zone. The risk that the participants should bear is reasonably divided by integrating expert evidence information, thus ensuring the accuracy, rationality and feasibility of the model. The risk sharing model can provide reference for the research on risk sharing of PPP projects in utility tunnel in the future.