The key structural parameters influencing the sealing performance of the intermediate rotating ring mechanical seals were analyzed via ANSYS.The results show that the extension elongation of both static ring and rotary ring has little influence on the sealing performance,while the thickness of intermediate ring and the sealing surface width have large influence on the sealing performance.The influence on sealing performance by the thickness of intermediate ring and the width of sealing surface is mutually independent.With the increasing of the thickness of intermediate ring,both of the highest temperature and maximum equivalent stress are decreased,however,the maximum contact pressure and leakage are increased.With the increasing of the width of sealing surface,the highest temperature,maximum equivalent stress and leakage are increased,while the maximum contact pressure is decreased.The structure of seal ring was optimized to obtain the optimal extension elongations of static ring and rotary ring,thickness of intermediate ring and width of sealing surface.After optimization,the highest temperature,maximum equivalent stress and maximum contact pressure of the mechanical seal are decreased,which are more favorable to the operation of mechanical seals.