In the face of a new round of scientific and technological revolution, combined with the tightening external environment faced by China and other problems, “big country heavy equipment” leading manufacturing enterprises need to further release innovation momentum and play a leading role in innovation to enhance industrial competitiveness by leading double-chain integration. Based on the longitudinal case study of CRRC Zhuzhou, the evolution process and mechanism of double-chain integration in the process of enhancing industrial competitiveness of leading manufacturing enterprises are deeply discussed. It is found that the leading enterprises’ leading double-chain integration goes through three stages of “accumulation, fission and climbing”, and the industrial competitiveness goes through a continuous evolution process of forming self-generating ability, focusing and reshaping ability and obtaining upgrading ability, and the adaptation mechanism, coordination mechanism and integration mechanism play a key role in the process.