The development of deepwater oil fields faces numerous constraints, such as platform weight and space limitations, as well as restrictions on enhanced oil recovery schemes, posing economic and environmental challenges. The onshore Carbon Capture, Utilization, and Storage-Enhanced Oil Recovery(CCUS-EOR) development mode is not entirely applicable. Deepwater CCUS-EOR technology adopts a production-capture-utilization-storage process based on multi-stage treatment of produced gas, establishing a zero-emission, offshore oil, gas, and water closed-loop processing system centered around the Floating Production Storage and Offloading(FPSO) unit, achieving minimum CO2 emissions during the processes of oil and gas extraction, processing, storage, and transportation. Under the production constraints of the offshore closed-loop processing of produced fluids from FPSO, a development method of combining high CO2 content miscible produced gas and water alternating flooding for oil recovery has been implemented, fully leveraging the synergistic advantages of the two-injection media to enhance oil recovery. Deepwater CCUS-EOR technology requires the optimal selection of injection parameters and the adoption of a deepwater CCUS-EOR reservoir management system, thereby achieving the best results in enhanced oil recovery and CO2 storage. The deepwater CCUS-EOR technology, under the FPSO production and recycling injection of produced gas method, provides a new solution for the green development of deepwater oil fields and is of significant importance for promoting the low-carbon transformation of the global energy industry.