In order to improve the service life of rubber joints of standard subway gearbox boom,the causes of fatigue failure of rubber joints are analyzed,the characteristics of different structures of rubber joints are studied,a new rubber joint with oblique linear rubber free surface and rubber thickness gradient is designed,the friction amplitude and stress concentration of rubber free surface are reduced,and by using finite element analysis software,the fatigue resistance of the new structure is optimized to improve by optimizing the fatigue resistance of the new structure using FEA software,the structural design defects are improved and the service life of the product is increased.