Abstract: In order to study the occurrence mechanism of the coal and gas outburst,based on the hypothesis of the comprehensive effect whioh mentioned three factors to control the coal and gas outburst,the self researched and developed simulation experiment platform ofthe coal andgas outburst was applied to make the physical simulation experiment of the coal and gas outburst under diferent gas pressure different vertical stress and different coal strength.The experiment results showed that the outburst intensit would be increased with the gas pressure in thecoalincreased and would be increased with the vertical geostress increased.Under the condition of the vertica d,the increased amplitude of the outburst intensity would be increased.And with coal intensity increased,the intensityof the coal and gas outburst would be increased in linear.