PPP modes at present in the field of road infrastructure in China are widely used, the value of highway PPP project is the focus of academic research, due to the uncertainty of the project, especially highway traffic volume is hard to predict, thus on the highway PPP project risk sharing and PPP project value evaluation are become hot concerned. In this paper, we consider the option value of the minimum traffic volume guarantee, estimating value of PPP project from the angle of real option, taking into account the risk of reasonable allocation, the bargaining game theory, based on government and private organizations on both sides of the risk preferences of the minimum traffic guarantee Value distribution. Finally, a highway PPP project is based on the application of government guarantees and risk preferences.