Business model innovation is an important support for the innovation of technology of manufacturing enterprises in digital economy era. Based on the viewpoint of business model innovation， it elucidated the theoretical mechanism of business model innovation affecting breakthrough capability of enterprises’ key core technology. Using the data of listed manufacturing companies in the key core technology field from 2011-2021， the impact of business model innovation on breakthrough capability of enterprises’ key core technology was empirically tested. It finds that business model innovation significantly improves breakthrough capability of key core technology， and the conclusion robustly established. The heterogeneity analysis shows that business model innovation has a facilitating effect on breakthrough ability of enterprises’ key core technology， and state-owned enterprises are significantly stronger than non-state-owned enterprises， large enterprises are stronger than SMEs， and enterprises in the eastern region are significantly stronger than enterprises in the central， western and northeastern regions. The mechanism test shows that business model innovation improves breakthrough capability of enterprises’ key core technology through intellectual capital accumulation effect， R&D investment guarantee effect and R&D product demand effect. The findings provide a theoretical basis and policy inspiration for promoting enterprise business model innovation and thus facilitating breakthroughs of key core technology.