Abstract: Aiming at gas and coal outburst occurring in 8^th coal seam at Cuizhuang mine, the analysis of characteristic and geological conditions about coal bed is carried on, and then the author points out the fundamental reasons of gas outburst. On the one hand, the closed structure from igneous rock's invasion well preserved coal-generated gas in this region, accordingly resulting in its high gas content, pressure; on the other hand, geological structures, such as fault, fold, etc, not only lead to stress concentration, but also damage the structure of coal, reducing itself resistance. Finally the control measures are put forward based on analyzing the reasons of gas and coal outburst of 8^th coal seam.