At present, China is at a critical stage of advancing industrial structural transformation driven by new quality productive forces and accelerating the realization of high-level scientific and technological self-reliance and self-strengthening. The deep integration of the talent chain, capital chain, innovation chain, and industrial chain has become a core lever for bridging the last mile of innovation and overcoming bottleneck technological constraints. To this end, from a result-oriented perspective, this study defines the essential connotation of the deep integration of the four chains, constructs a sequential research framework for such integration, and, based on data from Chinese listed companies from 2011 to 2024, constructs 179 industrial chains to empirically examine the transmission mechanism, time-lag characteristics, and heterogeneous effects of the deep integration of the four chains at the firm level. The findings are as follows. First, talent and capital support the innovation chain, enabling each link of the innovation chain to significantly and positively drive industrial chain upgrading, thereby realizing the deep integration of the four chains. Second, the transmission among the links of the innovation chain exhibits time-lag characteristics, and the strength of the effect gradually declines as the lag period increases. Third, the heterogeneity analysis shows that the deep integration of the four chains is more pronounced in central and western regions, non-state-owned enterprises, and midstream firms in the industrial chain, with the marginal effect being particularly prominent in central and western regions. Based on the above mechanism, this study proposes policy measures to promote the deep integration of the four chains. First, in response to the problem of insufficient factor coordination at the front end of research and development, it is necessary to guide talent, fiscal funds, and social capital toward basic research and frontier technological breakthroughs. Second, to address bottlenecks in the transformation of innovation outcomes, a phased support mechanism covering research and development, pilot testing, and industrialization should be established, using pilot platforms, cost-sharing arrangements, and market access mechanisms to bridge the last mile of technology commercialization. Third, in response to integration gaps across regions, ownership types, and industrial chain links, differentiated policies and targeted empowerment should be implemented to strengthen innovation catch-up in central and western regions, promote complementary advantages between state-owned and private enterprises, and advance coordinated upgrading across upstream, midstream, and downstream segments of the industrial chain.