Taking the subway driving gearbox as the research object,the dynamics finite element analysis model of gear system is established including the structure sub-system and the transmission sub- system. Then the vibration response of gearbox is calculated with the help of the Newmark-β method and the structure noise test is also studied on the experimental bench of subway gearbox. On this basis,the influence of gear modification and speed on the vibration characteristic would be also studied. The result shows that the rationality of analysis method is approved by comparing computational results and experimental tests,the gear modification could effectively reduce the structure borne noise of gear transmission system,especially the structure borne noise at the excitation frequencies,the relationship between speed and structure borne noise is not a linear rule. The research result offers some academic reference for dynamic property design of subway gear system.