Amid increasingly intense global technological competition, the importance of breakthrough technological innovation for China's long-term competitive advantage and industrial transformation has been emphasized. How to promote such innovation through artificial intelligence (AI) in the digital era has become a key strategic issue for enterprises. Based on socio-technical system theory and dynamic capability theory, a theoretical model of "AI capability – knowledge dynamic capability – breakthrough technological innovation" was developed to examine the internal mechanisms. Questionnaire data were collected from 312 enterprises to conduct empirical analysis. The findings indicate that AI capability significantly promotes breakthrough technological innovation. Knowledge dynamic capability plays a mediating role, especially in the dimensions of knowledge creation and knowledge integration, where strong positive effects were observed. Furthermore, a data-driven culture serves as a moderating factor, strengthening the influence of AI capability on breakthrough innovation. These results contribute to a deeper understanding of how breakthrough technological innovation can be achieved in the digital era through AI.