The rotation of the transmission shaft will cause vibration of the contact surface of mechanical seal friction pair during the operation of rotating equipment.In order to study the effect of contact face vibration on seal performance,the friction pair of a certain type of mechanical seal was taken as the research object,and the finite element model of the movable ring of mechanical seal was established by using SolidWorks.The structural dynamics analysis of the movable ring of the mechanical seal was carried out by ANSYS Workbench.It is found that a relative torsion in the radial direction is produced at the first,second and thirdorder modal frequencies,both sides of the movable ring will bend toward the center of the circleat the fourthorder and fifthorder modal frequencies,the sealing surface swings along the radial direction at the sixthorder and seventhorder modal frequencies,the end face produces relative stretch at the eighthorder modal frequency,and the end face produces a large deformation at the ninthorder and tenthorder modal frequency.According to the finite element analysis results,the firstorder modal frequency was selected and verified by the mechanical seal test bench.The results shows that the lowfrequency resonance of the mechanical seal caused by the rotation of the motor makes the outer diameter of the movable ring wear seriously,and the size of friction surface is different and the friction surface is discontinuous.The static ring fitted on the shaft is hardly affected by the vibration,and the friction surface of the end face is relatively uniform.The structural dynamic analysis of the mechanical seal moving ring is of great significance for reducing the leakage of the mechanical seal and prolonging the service life of the mechanical seal