How Does Digital-Green Synergy Affect Key Core Technological Innovation in China? Empirical Evidence from A-Share Listed Companies

Amid the rapid expansion of the digital economy and the advancing green transition, integrating digital and green technologies has become a vital corporate strategy for overcoming technological barriers and building competitive advantage. Analyzing 43,354 firm-year observations from Chinese A-share listed companies (2011–2024) using two-way fixed effects models, this study demonstrates that digital-green synergy substantially boosts innovation in key core technologies. A one-standard-deviation increase in synergy corresponds to a 7.3% rise in key core technology patent applications—a finding robust to endogeneity checks and sensitivity analyses. The effect is channeled through strengthened dynamic capabilities and corporate reputation, although technological volatility dampens this relationship. The benefits are more evident in regions with advanced digital finance, stronger human capital, and stricter intellectual property protection. Additionally, such synergy enhances innovation sustainability and generates knowledge spillovers across supply chains. These results underscore the need for policy frameworks that institutionally and operationally integrate digital and green initiatives to foster breakthroughs in core technologies.