The integration of digital economy and real economy by strategic emerging enterprises is a key driver to enhance the new quality productivity of enterprises. Using a sample of A-share listed strategic emerging firms from 2010 to 2021, this study empirically examines the impact of digital-substantive integration on the development of new quality productivity. The findings indicate that digital-substantive integration significantly promotes the formation of new quality productivity in these firms. This conclusion holds after addressing endogeneity concerns and conducting multiple robustness checks. Heterogeneity analysis reveals that the promoting effect of digital-substantive integration is stronger in regions characterized by well-developed new infrastructure, high levels of intellectual property protection, a strong concentration of scientific and technological talent, and stringent environmental regulations. Mechanism analysis further demonstrates that digital-substantive integration fosters new quality productivity through innovation transformation, supply chain restructuring, and strategic reform. These findings provide both theoretical support and empirical evidence for strategic emerging firms to advance digital-substantive integration and accelerate the development of new quality productivity.