The third plenary session of the 20th Central Committee of the Communist Party of China proposed implementing fiscal, taxation, financial, investment, pricing policies and standard systems to support green and low-carbon development, and also emphasized optimizing government green procurement policies. Green innovation embodies the dual development concepts of innovation and sustainability. Understanding how to leverage green fiscal policies to incentivize green innovation across enterprises at different development stages is of significant theoretical and practical importance for promoting the comprehensive green and low-carbon transformation of the economy and society. This paper uses Chinese “government procurement-listed companies” matching data as the research sample to explore the impact of government green procurement on enterprise green innovation from a dynamic lifecycle perspective. It is found that government green procurement significantly improves the level of green innovation of enterprises in the growth period, but does not significantly affect the green innovation of enterprises in the maturity and decline periods. Mechanism analysis reveals that government green procurement promotes green innovation in growth-stage enterprises by alleviating their financing constraints, enhancing market profitability, and optimizing green governance. However, it fails to effectively stimulate the willingness for green innovation or increase the risk-taking propensity of firms in the maturity and decline stages. Mechanism analysis shows that government green procurement can help enterprises in the growth stage ease financing constraints, improve market profitability and optimize green governance, thus promoting their green innovation. However, such procurement behavior fails to effectively stimulate the green innovation willingness of enterprises in the maturity and decline stages and cannot enhance their risk-taking ability. Compared with local government procurement, central government procurement plays a more significant role in promoting the green innovation of enterprises in the growth stage. In addition, the higher the environmental regulation intensity of the city where the enterprise is located, the more prominent the promotion effect of government green procurement on the green innovation of enterprises in the growth stage. The marginal contributions of this paper are as follows. First, it analyzes the differentiated sources of government green procurement on promoting corporate green innovation from a lifecycle perspective, and further explores the mechanism of green procurement at different lifecycle stages, thus expanding the understanding of the green innovation incentive effect and implementation path of government green procurement from a life cycle perspective. Second, in the mechanism analysis, it examines the impact of government green procurement on the green innovation willingness of enterprises at different life cycle stages of their lifecycles, revealing the underlying reasons for the differential effects of government green procurement policies on enterprises in the growth and decline periods. Third, from the two dimensions of procurement type and external environment, it empirically tests the moderating effect of government green procurement on enterprise green innovation, providing empirical evidence for the government to strengthen the effectiveness of green procurement policies and formulate targeted policy measures. The research conclusions indicate that: First, the positive role of government demand in guiding enterprise green innovation should be emphasized. When increasing the scale and scope of government green procurement, the differences in the life-cycle stages of the procured enterprises should be fully considered to better stimulate the green innovation vitality of enterprises; Second, the different guiding effects of central and local government procurement policies should be distinguished, and the demonstration and leading role of central government procurement should be brought into play.