Abstract: In order to determine coal and gas outburst risk degree of coal seam accurately and be easy to manage outburst mine hierarchically, studying risk indicators of outburst and index weight assignment method emphatically, we propose an attribute synthetic evaluation model for predicting the risk of outburst based on attribute mathematics theory and combined weight. An evaluation index system is established, which includes gas pressure, the initial speed of methane diffusion, the damage type of coal, the rugged coefficient, the depth ratio and coal thickness coefficient of variation. The multiplicative integration method is used to combine analytic hierarchy process and similarity coefficient method, and M₈ coal seam of Shihao Coal Mine is evaluated by the model. The results showed that gas pressure and the initial speed of methane diffusion exceeded the standard seriously, gas extraction drilling appeared intense jetting phenomenon in M8 coal seam. So, Shihao Coal Mine belongs to strong outburst coal mine.