Abstract：Underground coal will form goaf after mining. The existence of the goaf not only seriously affects the safe production of coal and the layout of the mining and excavation working face, but also has a serious impact on the seismic exploration of the lower coal seam. How to realize the effective exploration and identification of goaf and its lower coal seam is of great significance to the full utilization of coal resources and the safe and sustainable development of coal mines. In this paper, the corresponding model of the cavity period, collapse period and stable period after the formation of the goaf was established by the full wave field seismic simulation software. By analyzing the display characteristics of the lower coal seam on the time profile, it was found that the newly formed goaf had the greatest impact on seismic exploration. And after the collapse was stable, the lower coal seam reformed a continuous and stable reflected wave.
