In order to avoid failure and fault of mechanical device caused by the aging of rubber O-ring,it is urgent to study the non-destructive,on-line and quantitative detection method for rubber seal structure aging state.The finite element model of rubber O-ring seal structure was established based on ANSYS software.Different aging states of equivalent models were achieved by using different input parameters.The aging modal analysis of rubber O-ring seal structure with compression ratio of 20% was completed.The relationship between aging state and natural frequency was established.The results show that the established finite element model can reflect the change of aging state characteristics of rubber O-ring seal structure,and provides a priori knowledge for the study of non-destructive,online and quantitative detection method of rubber seal aging state.