Against the backdrop of technological monopoly in Europe and the United States, production advantages in India and other countries, and the double pressure of China's “dual-carbon” target, China has to face the process of transition from traditional fuel vehicles to new energy vehicles. Based on this background, this paper explores the issue of green sustainable development among consumers, producers and the society under the government's two policies of car purchase subsidy and electricity tax. The results of the study show that: firstly, the incentive effect of vehicle purchase subsidy on new energy vehicles is not obvious, and there may even be a risk of reducing the purchase of new energy vehicles, thus failing to achieve the environmental protection goal; secondly, when the increase in the gradient levy of electricity charges prompts the market to choose vehicles with higher energy efficiency ratings, the dual impacts of the quantity and the energy consumption ratings can be more effective to promote the green development; and lastly, under the overlapping impacts of the two policies, both of them may cancel each other out, and differences in the predominant outcomes of the policies can lead to differences in the level of greening.