Lead-cooled Fast Reactor (LFR) have the advantages of good neutron economy and excellent coolant thermal characteristics. However, due to the corrosiveness of liquid metal on structural materials and the dense rod bundle structure of fuel assembly fixed by wire, the flow path is narrow, and the blockage is more likely than that in water-cooled reactor. In this paper, the blockage experiment and numerical simulation of LFR are investigated, and the current blockage situation of liquid metal cooled fast reactor is summarized. In addition, we used severe accident analysis program CODA to simulate the temperature field and flow field of the LFR of China initiative Accelerator Driven System (CiADS) when the maximum power fuel assembly is partially blocked, and the influence of partial blockage on LFR is evaluated. The results show that radial flow occurs in both the upper and lower sides of the blockage, and the axial flow above and below the blockage decreases. The maximum fuel pellet temperature, the maximum cladding temperature and the coolant temperature of the blocked fuel assembly all increase in different amplitude, but did not reach the cladding melting temperature, and the integrity of the cladding was not damaged.