To study the vibration and noise characteristics of elevated railway bridge structures and the influencing factors, a certain elevated railway bridge on the Shanghai-Kunming high speed railway was taken as the research object, a hybrid FE-SEA model for numerical simulation analysis was established and on-site experimental verification was conducted. Accordingly, the influence of plate thickness on structural noise and the contribution of each bridge plate subsystem to the overall noise were analyzed. The results showed that the FE -SEA method is suitable for the study of structural noise of elevated railway bridge. The peak frequency of vibration for the box girder structure is 125 Hz. and the frequency of structural noise ranges from 50 Hz to 160 Hz. The top plate and wing plate of the box girder contribute considerably to the far-field sound pressure level. The results indicated that increasing the thickness of each plate can reduce the structural noise, and this reduction is greater when the thickness of the top plate is increased.