Abstract: In this paper, the research background for the advanced accident-tolerant fuel (ATF) pellets was summarized, focusing on the R&D status of accident-tolerant UO2-based composite fuel pellets at home and abroad. It is concluded that the UN, U3Si2 and ThO2 are doped phases with the most development potential for accident-tolerant UO2-based composite fuel pellets. However, the optimal adding quantity and distribution of these doped phases should be investigated further by multi-scale modeling combined with experiments.