Abstract: Breaking through key core technologies has been a major issue related to China's overall development, which is also the key to promoting the new development pattern of domestic and international dual cycles. Practice shows that after decades of development, Chinese equipment manufacturing industry, as a pillar industry of the national economy, has achieved long-term progress. However, equipment manufacturing enterprises are still far away from being completely independent and controllable in key core technologies. Facing the squeeze of the competitive market and international political sanctions, it has become extremely urgent to solve the problem of how to break through key core technologies. Existing research on how to break through key core technologies only focuses on macro-level discussions and initiatives like emphasizing the importance of leading enterprises, or only discusses the realization of single core technologies. There is a lack of research on the breakthrough path to systematically explore key core technologies of complex products at the enterprise level. Given the gaps in existing research and important practical significance, this study aims to investigate the breakthrough path of key core technologies for leading equipment manufacturing enterprises. To solve this question, we choose the exploratory case study method to explore the dynamic process of two leading equipment manufacturing, XCMG and WEICHAI, in achieving technological breakthroughs. Specifically, we put forward two research questions in this research: First, what are the evolution characteristics and realization paths of leading equipment manufacturing enterprises realizing technological breakthroughs? Second, what are the core elements that support leading equipment manufacturing enterprises to achieve key core technologies? On one hand, we fully collect the information and data of the cases, and code data to obtain the key constructs and research frameworks——technological breakthrough paths, technological innovation capabilities, and breakthrough results. Among them, we aggregate the core elements from the perspective of technological innovation capabilities. On the other hand, according to the research framework, we sort out the technological process of the cases in stages, and finally condense the core elements that promote enterprises to realize technological breakthroughs. The research results show that: First, the key core technology breakthroughs achieved by the leading equipment manufacturing enterprises have the characteristics of multi-technology concentrated breakthroughs and multi-product co-innovation. Specifically, the technological breakthrough path at the enterprise level can be divided into four stages, which is from technology introduction, technological improvement, independent innovation to global leadership. The product evolution characteristics corresponding to each stage are as shown below: Product component manufacturing, overall manufacturing, overall self-developed, and leading the world. The characteristics of technological evolution corresponding to each stage are as shown below: The overall introduction, partial technological improvement, technological innovation, and centralized technological breakthroughs. Second, the core elements to achieve technological breakthroughs include continuous large R&D investment, technology accumulation, human resources including leading entrepreneurs, technical experts and talent management systems, R&D organization system, IUR cooperation, and internationalization strategy of technological innovation. This study contributes to the prior literature in three main ways. First, this study adds to research on key core technologies. Existing research on key core technologies is only at the stage of emphasizing its importance, and there is still a lack of rigorous and systematic academic research. This study explores the breakthrough path of key core technologies of China's leading enterprises in equipment manufacturing industry, and summarizes the key elements. Second, this study promotes the research on technology upgrading of complex products. Different from previous research that focuses on the evolution of a single technology and its internal structure, this study portrays the evolutionary characteristics of Chinese leading equipment manufacturing enterprises to achieve technological breakthroughs in complex products. Third, in addition to exploring the breakthrough path of key core technologies, this study also pays attention to the technological innovation capabilities that support enterprises to achieve technological breakthroughs, thus enriching research on the evolution of technological innovation capabilities. For practical implications, we suggest that enterprises should clarify their current stage of technological innovation, and pay attention to and strengthen the input of core elements. For example, enterprises can plan for the long-term large R&D investment and international technology-oriented strategy, pay attention to the introduction and cultivation of leading talents and professionals, and strengthen the governance of IUR alliance portfolios. Besides, the government should effectively construct and implement systems as well as policies that are conducive to technological breakthroughs in enterprises, and actively build bridges for innovative leading enterprises to achieve domestic and international development.