The rapid development of modern aircraft technology is increasingly demanding aero-engines. It not only requires aeroengines to ignite and take off under suitable conditions, but also faces various severe weather and foreign object impact tests during flight. The stress variation caused by the impact of an aero-engine fan blade is studied. Because the compressor guide vane has a small solidity, the hail may not only hit the vane when striking the blade, but also may hit the first-stage rotor blade. The effects of hail impact on the vanes and rotor blades, especially the impact on the blade strength, were studied. Firstly, the UG software is used for geometric modeling based on the existing vane and rotor geometry data. Secondly, the ANSYS/LSDYNA software is used to simulate the process when the hail hits different positions of the blade and rotor at different speeds. To explore the influence of hail impact on the blade. It is found that when the hail hits the guide vane, the maximum effective stress of the vane does not exceed the yield stress of the material. When the hail hits the rotor, the maximum effective stress of the rotor is closely related to the rotor speed, the hail incident velocity, and the relative position of the rotor and the hail. When the impact is severe, the maximum effective stress will exceed the yield stress of the material, and even the blade may be bent and pitted, which has an important impact on the strength and life of the blade.