Abstract: In order to reveal the law of propagation and attenuation of vibration in tunnels under frequent blasting, a 3D tunnel model is built by LS-DYNA based on the Duanjiaping tunnel on the Inner Mongolia-Jiangxi Railway, and the propagation laws of blast-induced vibration in the near area, medium and far area are simulated and analyzed. The results show that the vertical peak vibration velocity of the particle decreases with the increase of distance and blasting times except for a few exceptions; the attenuation of vibration velocity in the near area is faster than that in the medium and far areas; the value of α in the medium and far area is at least 12.5% smaller than that in the near area, and as a whole the values of α in this two areas increase slowly with the increase of blasting times;the coefficient K decreases with the increase of number of blasting, the reduction rate of K in the near area is generally greater than that in the medium and far area and the value of K in the near area is at least 29.1% higher than that in the medium and far area; the parameters of the medium and far area are more consistent with the Sadovsky empirical formula than that in the near area under frequent blasting.