Abstract: The reactor vessel serves as the first safety barrier for the core of sodium-cooled fast reactors and its integrity is crucial throughout the service life of the reactor. Compared to the development level of in-service inspections of fast reactors abroad, the in-service inspection of domestic fast reactor vessels is still in its infancy. This paper comprehensively considered the determination of inspection processes and the implementation of inspection devices for the in-service inspection of fast reactor vessels. It analyzed key technical issues such as the selection of ultrasonic inspection probes, cooling of visual inspection cameras, and conceptual design of inspection devices. Additionally, by comparing the advantages and disadvantages of foreign inspection schemes based on the development of in-service inspection technology for fast reactor vessels internationally, it sought to find potential solutions for the full-life in-service inspection of domestic fast reactor vessels. Finally, using the Chinese Experimental Fast Reactor (CEFR) vessel as the subject of inspection, the feasibility of the proposed solutions was verified, providing a reference for in-service inspection personnel of fast reactors.