This paper analyzed the pricing mechanism in the supply of public goods，based on defining the calculation of social welfare which considered part of producer surplus in the operation of PPP project under the guidance of government，and classifying the public goods market into three states i． e． ，the high，middle and low demand needs． By analyzing the different allocations of pricing right between public and private sectors， and then maximizing the different benefits individually by public and private sectors，it derives the pricing mechanism and the different impacts of related parameters on it under three different demand states，examined the relationship between the interval of price regulation by government and the cost in the operation of public-private partnership projects，and also find the different correlations between the pricing and the demand elastics of public goods in different market demand levels，so as to bring forward some suggestions for pricing of public goods in the practice of PPP projects．