Objective This paper studies the supply chain of new energy vehicles composed of a manufacturer and a franchised store and considers the impact of differentiated government subsidies on the supply chain of new energy vehicles when the manufacturer?? s cost information is asymmetric. Methods A principal-agent model between the manufacturer and the franchisee was established using game theory a franchise sales contract was designed and the model was solved using a non-linear optimization method in operations research. The effects of asymmetric information and government subsidies on supply chain participants and the superimposed effects of government subsidies on the value of information were analyzed and numerical examples were given. Results Differential subsidies always provide incentives for manufacturers to improve the greenness of their products and green production efficiency resulting in increased profits for the franchise. Information asymmetry will lead to the profit loss of the franchise. Only when the production efficiency is high can manufacturers obtain information rents from asymmetric information. Low-cost type manufacturers will always only gain retained profits. Regardless of efficiency subsidies always further exacerbate the information disadvantage of the franchise. When the manufacturer?? s production efficiency is high the profit within the supply chain can be transferred without damaging the overall benefits thus avoiding the adverse effects brought by asymmetric information. Subsidies will further increase the impact of asymmetric information on the supply chain and will vary with the level of green production efficiency of manufacturers. Conclusion Differentiated subsidies can inspire franchises to work with green and productive vehicle manufacturers thereby promoting sustainable development and transformation and upgrading of the new energy vehicle industry. Asymmetric information has an impact on the returns of manufacturers and franchises. Subsidies can expand the information advantage of the efficient manufacturer and have a superimposed effect on information value.