Owing to that the government has taken most of the income risk for the private sector through the minimum income guarantee in PPP projects, the public sector has a strong position in the allocation of excess income. The bargaining model for allocation of excess income of PPP projects under the condition of unequal status of public and private sectors is established. The real negotiation process of the excess income of PPP projects is simulated so as to provide decision-making basis for the scientific, reasonable and equitable allocation of the excess income of PPP projects. The key factors for the allocation of excess income of PPP projects are obtained through the analysis of the results.