Abstract: The rationality and validity of the reservoir PPP project is not only the key to the successful implementation of the reservoir PPP project, but also the key factor to improve the efficiency of all participants involved in the project. Based on the CAPM model, the paper puts forward the investment yield rate CAPM model of the reservoir PPP project. It constructs the concession price model of the reservoir PPP project by comprehensive considering the five key factors such as the concession duration, the investment yield rate, the project investment, the annual water supply volume, the rate of the inflation and the cash flow analysis principle as the theoretical support. The model is used to simulate the concession price of a reservoir PPP project. The simulation result is closer to the actual value of the projet concession price. Thus it shows that the model is scientific, reasonable and practical. Finally, the conclusions of the research are summarized, and the suggestions for improving the concession price theoretical system of the reservoir PPP project are put forward.