A higher requirement is proposed for the sealing performance of the sealing ring used in the shield machine main bearing.The force condition was researched for the lip type seal with crimp ring made by different materials under different preloads with the finite element analysis software ANSYS Workbench,and its sealing performance was also researched.The analysis results show that the sealing performance of lip type seal with crimp ring has relationship with both of its materials characters and preloads.The higher values of hardness and preloads of sealing ring,the contact pressure of sealing surface is more greater,and the sealing capability is more stronger.Therefore,in order to improve the sealing performance of the main bearing sealing rings the shield machine with large depth,the following measures can be taken: choose the sealing rings with crimp ring with high hardness for materials,increase the number of sealing ring if necessary,and increase the diameter of crimp ring for structure to make sure that the crimp ring gives much larger preload to the lip type seal and improve the contact pressure of sealing surfaces.