Abstract: The integration of rare earth conglomerates is a crucial means to enhance the competitiveness of the rare earth industry chain and the stability of the supply chain. This study conducts an in-depth analysis of the evolution process, mechanisms, and primary effects of the integration of rare earth conglomerates in empowering the extension of the industry chain. The research findings indicate that the evolution process of the integration of rare earth conglomerates in China can be broadly divided into four stages: the period of idea germination （1999-2010）, the period of accelerated advancement （2011-2014）, the period of initial formation （2015-2020） and the period of deepening and transformation （2021 to the present）. The integration of China’s rare earth conglomerates has empowered the extension of the rare earth industry chain through channels such as enhancing supply chain stability, promoting effective resource coordination, and improving technological innovation levels. The integration of China’s rare earth conglomerates has achieved certain positive results in empowering the extension of the industry chain, but the synergistic effects of resources and technological innovation have not yet been fully realized. Based on this, it is recommended that the government further promote the orderly and effective development of overseas medium- and heavy-rare earth resources by rare earth conglomerates, genuinely enhance the resource synergy effects of the integration of rare earth conglomerates, leverage the role of rare earth conglomerates as leaders in the industry chain, and guide the two major rare earth conglomerates to collaborate with leading enterprises in the downstream of the industry chain on technological breakthroughs or mergers and acquisitions. This study not only helps to comprehensively and objectively understand the process and effects of the integration of China’s rare earth conglomerates in empowering the extension of the industry chain, but also provides decision-making references for the government to further leverage the role of the integration of rare earth conglomerates and enhance the resilience and security of the rare earth industry chain and supply chain in the context of the evolving global rare earth supply landscape.