The selection of publicprivatepartnership (PPP) modes is very important for successful operation of PPP project of urban underground utility tunnels. The characteristics of the utility tunnel project and the PPP modes are analyzed; and 7 kinds of PPP modes suitable for the construction of utility tunnel to simplify the filter process are identified. And then the evaluation index system for PPP mode selection is established; and the weights of indexes are calculated by ordered weighted averaging (OWA) operator. Finally, the extensible matter element is used to quantify the privatization degree of the indexes of PPP modes; and the correlation function is used to determine the suitable degrees of every PPP mode to utility tunnels. The application of PPP mode selection to Xi′an underground utility tunnels has verified the scientificity and operability of the abovementioned method.