The deep sea is not only a mystery of life and repository of resources, but also a critical element of national security, constituting a vital strategic domain for the sustainable development of humanity. To develop China into a strong maritime nation, it is imperative to advance into the deep sea. To this end, the 2025 Government Work Report has, for the first time, identified "deep−sea science and technology" as an emerging industry. This article highlights that, thanks to rapid advancements in "deep drilling, deep diving, and deep−sea networking" technologies, China has developed world−class capabilities in "deep−sea access, deep−sea exploration, and deep−sea development." Significant progress has been made in areas such as deep−sea drilling, deep−sea diving, and deep−sea observation networks. Notably, the "South China Sea Deep−Sea Research Initiative" has achieved breakthrough results, including the discovery of low−latitude drivers. In the future, exploration in the South China Sea will expand to the southern basin, and China’s deep−sea research will advance toward full−ocean−depth and all−sea−area investigations, promoting deeper integration between deep−sea and polar exploration.The deep sea holds abundant and valuable resources. Currently, China faces a historic opportunity to establish a "Chinese School" of Earth system science, starting from deep−sea research. It is essential to build upon the foundation of the South China Sea, broaden the perspective to the global ocean, accelerate the strategic development of deep−sea science and technology, foster new productive forces in deep−sea resource utilization, and promote the intelligent integration of "deep drilling, deep diving, and deep−sea networking" technologies with multidisciplinary collaboration. Leveraging new technologies such as big data and supporting technological innovations will provide crucial support for China’s goals of becoming a maritime power and a global leader in science and technology.