Abstract: In order to assess the risk of coal and gas outburst and avoid the incompatibility of each factor and subjectivity, the twelve indexes of the risk of coal and gas outburst are selected from three aspects including ground stress, gas potential and physical property of coal, a evaluation model based on extension goodness evaluation and Enshi State of different categoried is proposed. Then, a matter-element model of coal and gas outburst risk assessment is built according to extenics method and the matter-element model is solved by using extension goodness evaluation. Indexes weight are calculated by Enshi State of different categories, goodness sort of three coal seam risk is obtained. Finally, this model is compared with the TOPSIS method by entropy weight. The result shows that this method is objective, clear, simple calculation and practicability.