The working principle of the Second Used Sayaji Roll Crusher determines that the working environment of the rotor is very harsh. The rotor often needs to withstand the random impact and centrifugal force from the material when it is working, and it must also withstand the vibration caused by the vibration motor. The excitation of these factors will cause the rotor to resonate, causing the rotor to crack or even break. Therefore, it is necessary to perform modal analysis on the rotor. The modal analysis of the rotor is the basis for the dynamic analysis of the rotor. The modal analysis of the rotor can evaluate the dynamic characteristics of the rotor. When designing the structure of the rotor, it must be considered whether the excited frequency of the structure is close to the structure. Natural frequency, to avoid the working frequency region of the rotor, to avoid the occurrence of resonance phenomenon, which will cause damage to the rotor. The modal analysis of the rotor is mainly to determine the structure and the vibration characteristics of the rotor in the design of the rotor, that is, the natural frequency and mode shape of the rotor, and the modal analysis of the rotor is the starting point of other dynamic analysis, such as transient dynamic analysis. , Harmonic response analysis, etc. The modal analysis can guide the experimental analysis of the rotor, that is, design the placement of the accelerometer, etc., and can also evaluate the changes and improvements in the design. Through the modal analysis of the rotor, the dynamic characteristics of the rotor can be obtained, which has great guiding significance for the design of the rotor structure and even the improvement of the performance of the impact crusher. When performing modal analysis, you can use the Simulation module in I-deas to obtain the natural frequency and free mode of the rotor body by establishing the finite element model of the rotor body in free modal, and obtain the rotor at various natural frequencies. The possible forms of vibration and the parts most prone to deformation provide a certain theoretical basis for the structural design and improvement of the rotor body.