Focuses on the fracturing phenomenon that occurs after the aging of the sealing structure at the interface of cast iron pipes,the structure of the sealing ring was optimized.Four new rubber sealing ring structures were proposed by reducing the compression rate of the soft rubber part of the original hard rubber and soft rubber combination sealing ring and improving the shape of the soft rubber part.Finite element simulation analysis was conducted on the rubber sealing ring using ANSYS,and static simulation analysis was conducted on the rubber sealing ring under the conditions of considering partial load and minimum compression.The results show that the new structure,which transforms the soft rubber part from circular to lemon shaped and reduces compression rate,has the best sealing performance.However,under eccentric loading,the stress concentration at the soft hard rubber connection is severe,and due to structural reasons,there is a stress “inflection point” at the head.The new structure is optimized,and the optimized structure can effectively improve the stress concentration phenomenon under eccentric loading and compression without reducing the sealing force.