Radiation safety technology is the fundamental guarantee for the radiation safety of marine nuclear power plants, and the radiation safety level need to be increased urgently in China. For the core technologies such as the technologies used in radioactive source item analysis and radiation shielding design, this paper surveyed the current research situation and development trend at home and abroad. From the perspective of development needs, the overall objectives, the key and difficulty and the development roadmaps of the technologies for radioactive source item analysis and radiation shielding design were proposed in this paper, which provided the direction and support for the development of radiation safety technology in marine nuclear power plants in China.