Abstract: In order to study the impeller erosion characteristics of the lead-bismuth axial flow pump, based on the analysis of the erosion damage mechanism of the liquid lead-bismuth, the mathematical model of erosion was established by using the boundary layer theory, and the SST k-ω turbulence model was used to numerically calculate the flow in the pump under three scenarios of 0.8Q_d, 1.0Q_d and 1.2Q_d, and the relationship between the distribution of the blade erosion and the wall flow velocity, flow pattern, wall entropy yield and erosion was obtained. The results show that the high impact erosion area is mainly distributed at the inlet edge of the blade near the pump housing. With the increase of the liquid lead-bismuth inlet flow and the increase of the wall flow disorder, the impact of the blade erosion increases. When the maximum flow velocity of the liquid lead-bismuth is not higher than 10 m/s, the impact of blade erosion is small, but when the maximum flow velocity is higher than 10 m/s, the blade surface erosion increases sharply. The high impact erosion area on the blade surface is the main distribution area of the high wall entropy yield, and the impact erosion behavior of the liquid lead-bismuth is positively correlated with the wall entropy yield.