Abstract: In view of the high requirements of Beijing rail transit new airport line on vehicle technical parameters, the performance of stiffness and fatigue resistance of conventional lateral buffer structure is analyzed, and an optimization scheme of lateral buffer is proposed, which integrates the peripheral metal and rubber by vulcanization and bonding. A finite element analysis model of lateral buffer is established to calculate its stiffness，then using fatigue curve and according to the fatigue cumulation rule under multistress and strain conditions, the fatigue strength of the optimized lateral buffer rubber elastomer is analyzed. The simulation results show that the optimized lateral buffer fully meets the operation requirements, and the test results show that the stiffness performance and fatigue resistance of the optimized lateral buffer meet the operation requirements as well.