In the actual operation process, the impact of particles will cause the leading edge to degenerate into a blunt shape, which will affect the internal flow field and lead to the decline of aerodynamic performance of the engine. Leading edge optimization based on blunt blades can restore its aerodynamic performance. In order to explore the influence of aerodynamic optimization process on the erosion rate of particle, in this paper, the fan rotor blade of a large bypass ratio turbofan engine was taken as the research object, and the steady numerical simulation method and unidirectional fluid-structure coupling calculation were used to study the erosion wear rate of particle. The results show that the erosion area is close to the leading edge of the blade, and the erosion rate increases with the increase of blade height. Most particles collide with fan blades at the pressure surface. The erosion rate is directly proportional to the concentration of particulate matter. Compared with the design point condition, the erosion area is closer to the leading edge of the blade at the surge point. The erosion rate of particle at the leading edge of blunt blade increases compared with that of the original blade. The optimized leading edge blade based on aerodynamic performance can reduce the erosion rate, but this law is not applicable to all positions.