Abstract: Based on the coal and gas outburst indicators measured data of Dingji 13-1 coal seam, factor analysis and evaluation model for coal and gas outburst was set up. Three public factors of coal and gas outburst in Dingji Coal Mine were proposed; they were mechanical factor, the physical properties of coal and gas factor.With the actual situation of coal and gas outburst in Dingji Coal Mine, the results show that coal and gas outburst was mainly affected by the ground pressure and was prone to coal and gas outburst (extrusion) with geostress.