Abstract:Key core technologies are critical to the quality of national economic and social development and industrial security. Building innovation ecosystems led by focal firms and involving multiple innovation actors represents an important approach to achieving breakthroughs in key core technologies. From the perspective of innovation ecosystems, this study investigates the formation mechanism and evolutionary trajectory of key core technology innovation ecosystems by adopting a single-case study and grounded theory approach, with Shanghai Micro Electronics Equipment (Group) Co., Ltd. as the research context. Drawing upon co-evolution theory and dynamic capability theory, this study explores how focal firms organize and mobilize heterogeneous actors under conditions of technological constraints. The findings reveal that, under the constraints of key core technologies, innovation ecosystems do not emerge naturally through market-based collaboration but are gradually constructed through the continuous organization and mobilization of focal firms. Specifically, focal firms overcome resource constraints through nonmarket strategies, establishing legitimacy and resource foundations for technological breakthroughs; they leverage market strategies to facilitate the application of technological achievements in specific scenarios and align technological capabilities with market demands; and they empower ecosystem factors to enhance resource connections and collaborative interactions among heterogeneous actors, including governments, research institutions, and financial institutions. Through this process, key core technology innovation ecosystems evolve through three stages: the task-driven stage, the market validation stage, and the ecosystem symbiosis stage, gradually shifting from initial task orientation toward capability-based symbiosis. This study provides theoretical insights into the formation of key core technology innovation ecosystems under technological constraints and offers practical implications for focal firms in organizing collaborative technological breakthroughs.