Abstract: Subway stations are of great crowd density and enclosure surrounding. Once accidental or terrorist explosion occurs inside them, the impact of blast wave on subway structure would be more severe, even cause serious damage of structures and a huge number of casualties. The propagation process of blast wave inside a subway station is numerical simulated, the propagation and attenuation law of blast wave are investigated, safe distances to avoid human casualties are determined, and effects of height of structure and distances of exit from explosive on propagation of blast wave are analyzed. The results show that the blast wave in the subway station is of a longer propagating duration, a slower attenuation, and larger damaging effects on the structure. Different heights of structures not only affect the attenuation of blast wave, but also cause the difference of waveforms. The venting effect of the exit is related to the distance of the exit from the explosive, and the closer the exit from the explosive is, the more remarkable the venting effect is.