The proposal and advancement of new quality productive forces have endowed firm upgrading in China with deeper implications. By lowering financing costs, optimizing resource allocation, and alleviating information asymmetries, digital finance may provide important support for firm upgrading. Based on panel data of 1,116 A-share listed firms in China from 2011 to 2023, this study constructs an index to measure the level of firm upgrading under the policy context of developing new quality productive forces and employs a multi-way fixed effects model to examine the impact of digital finance on firm upgrading. The results indicate that the development of digital finance significantly promotes firm upgrading, and that the innovation willingness of both governments and enterprises serves as an important mechanism through which digital finance exerts this effect. Moreover, digital finance markedly facilitates firm upgrading in the eastern region, with stronger effects observed in technology-intensive industries, high-tech firms, and small non-state-owned enterprises. Based on these findings, the study proposes targeted policy recommendations aimed at improving the institutional mechanisms for developing new quality productive forces in accordance with local conditions, thereby offering insights for research on firm upgrading under this policy framework.