Under the dynamic load of vehicle, the bridge will vibrate and radiate lowfrequency noise which is harmful to human health. A method for predicting the lowfrequency noise is proposed based on the analysis of vibration of bridge deck. The prediction includes the analysis of vehiclebridge coupling vibration considering the bridge deck and the analysis of sound radiation and propagation in the air. By taking a bridge with lowfrequency noise as example, the vibration and sound radiation of the bridge are analyzed respectively by the current method and the previous method based on the grillage model. The results show that the prediction based on the vibration of bridge deck is more accurate. Furthermore, the measures to reduce the noise of bridge are explored, and the results indicate that a smoother road surface leads to lower noise. But when the condition of road surface is up to the extremely good standard defined by ISO, the effect of reducing the roughness of surface is not significant. Also, strengthening the crossbeam in the bridgehead is a simple and effective way to reduce the lowfrequency noise of bridge.