Abstract: The financial policy of science and technology is a significant instrument for advancing an innovation-driven development strategy. However, the existing studies have primarily concentrated on the direct impact of the policy on innovation while overlooking the potential for indirect innovation spillovers. The “Pilot Policy of Promoting the Integration of Science, Technology and Finance” implemented by the Ministry of Science and Technology and five other departments in two batches is employed by this study as a quasi-natural experiment to investigate the innovation spillover effect of the science and technology finance policy and its spillover channels with a multi-period difference-in-difference method on the basis of the supply chain data of China’s A-share listed companies from 2009 to 2022. The results indicate that the pilot policy has innovation spillover effect and that the innovation level of suppliers in the non-pilot regions has been significantly enhanced. The spillover channel analysis demonstrates that the innovation effect of the pilot policy is transmitted from customers to suppliers through two main channels: the knowledge spillover channel and the demand-pull channel. Further research indicates that the innovation spillover effects of the pilot policy are more pronounced in the samples with higher switching costs for customers, superior absorption and transformation capacity for suppliers, robust intellectual property protection, and close proximity between suppliers and customers. Consequently, the government should further enhance and promote the pilot policy and enhance the innovation spillover effect of the policy by reinforcing the protection of intellectual property rights and encouraging collaborative innovation among enterprises, so as to improve the quality and efficacy of financial services for science and technology innovation.

Key words: science and technology finance, innovation spillover, knowledge spillover, demand-pull