Abstract:Deep-sea polymetallic oxide ores such as iron-manganese nodules and cobalt-rich crusts are rich in cobalt, nickel, copper, manganese, and rare metal elements. They are considered to be important key metal raw materials in the future, especially for the development of global green economy. Obtaining green key metals from deep-sea polymetallic oxide ore has become an important driving force to encourage deep-sea mining. Demand for key metals, land resource supply and price trends for development of green economy were summarized. Value composition of key metals in polymetallic nodules and cobalt-rich crusts were analyzed. Extraction technology of nickel, cobalt, copper, molybdenum, rare earth, platinum, and manganese from deep-sea polymetallic oxide ores were reviewed and analyzed. Development extraction technology trend of deep-sea key metals was analyzed from view of perspective of green, low-carbon, and maximum comprehensive utilization.