Taking breakthroughs in key core technologies to drive the construction of a modern industrial system is an inevitable choice for building a great modern socialist country. Based on network embeddedness theory and coupling theory，this study took China Aerospace Science and Technology Corporation （CASC） and its historically evolved institutions as research objects，and explored the specific process and internal mechanism of how enterprises' breakthroughs in core key technologies drive the construction of a modern industrial system. The findings are as follows:（1） Breakthroughs in key core technologies promote the construction of a modern industrial system by triggering internal and external network embedding，implementing resource actions，and adjusting network coupling relationships，which are phasedly manifested as system integration breakthroughs，system architecture transformation，and system integration and innovation. （2） With the upgrading of key core technology breakthroughs，enterprises sequentially adopt the action strategies of "construction-adaptation-resonance" for internal and external networks. Under the network embedding actions of "connected-intermediary-architectural" types，it implements resource aggregation，leveraging，and symbiosis actions in stages，thereby promoting the transformation of the internal and external network coupling relationship from the "dominant-response" type and the "exploration-adaptation" type to the "origination-resonance" type. （3） The modern industrial system presents an evolutionary law of "foundation-iteration-ecology"，in which future industries，emerging industries，and traditional industries undergo stepped transformation，while the three core characteristics of integrity，security，and advancement are interdependent and achieve coordinated upgrading. This study reveals the theoretical black box of constructing a modern industrial system driven by key core technologies，and will provide certain theoretical basis for accelerating the construction of a modern industrial system.