In order to explore the vibration characteristics and vibration transmission characteristics when the train passing through the viaduct of urban rail transit,taking an urban rail transit viaduct as the research object,the vibration test is carried out at different distances from the pier. The test results are analyzed in frequency domain. Then,the 1/3 octave are analyzed by using linear weighting and Z weighting,and the transmission characteristics of vibration under characteristic frequency are analyzed when two weights are adopted respectively. Finally,the transmission characteristics of equivalent continuous Z vibration level are analyzed. The results show that when the train passes through the urban rail transit viaduct,the vibration acceleration of the ground is mainly distributed in the 0~200Hz frequency range,and the peak value of vibration acceleration is mainly distributed in the frequency range of 60~80Hz. Under the linear weighting,the global peak of the vibration acceleration level of the ground appears at the frequency of 63Hz,and the local peak appears at the frequency of 4Hz. Under the Z weighting,the global peak value of the vibration acceleration level of the ground appears in the range of 50~63Hz,and the local peak values appear at the frequency of 4Hz. With the increase of the distance from the center line of the track,the acceleration level of the ground vibration decreases with the increase of the distance from the center of the pier to the ground,and the attenuation rate decreases with the increase of the distance from the center line of the track.