This study highlights the importance to develop a scientific mathematical allocation model that is operable and practicable, explores the relationship between vehicle fuel consumption and the various influencing factors. Apart from the factors recognized in the previous studies, such as cylinder, displacement and weight, this study addresses the significance of the involvement of road and environmental factors in vehicle fuel consumption. By analyzing the data obtained from Management System, the impacts of various factor coefficients are determined. An evaluation index system for bus fuel consumption is designed, and a model of allocating the subsidy is constructed. Besides, managerial implications are also discussed in this paper.