Based on externality theory and public goods theory, this paper studied the government's green procurement intervention of supplier behaviour under the completely competitive market structure and imperfectly competitive market structure, and then theoretically demonstrated the effect of environmental pollution intervention on China's new energy vehicles. The government procurement as an example analysed the green intervention effect of government green procurement. According to the theoretical and practical argumentation conclusions, the following measures were proposed: further expand the scale of government green procurement; give green product purchase prices to be tilted; improve green standards or evaluation systems and establish and improve government green procurement regulations.