Abstract: Aiming at the shortcomings of the “three-rate method” in determining the sensitive indicators for coal roadway outburst prediction and the threat of outburst to personnel during detection, in this paper, a laboratory method for determining the sensitive index and critical value of coal roadway outburst prediction is presented. According to the principle that the apparent density and moisture of simulated soft stratification are consistent with the original coal seam in the field, the forming pressure and pressing steps of simulated soft stratification were determined. Then filling the simulated soft layer with low pressure and high pressure gas, drilling and measuring various coal roadway outburst prediction indexes respectively, the relative sensitivity of each predictor is known and one of the highest predictors of sensitivity can be obtained. Through outburst simulation or measuring the initial release gas expansion energy, the critical value of the index can be determined. Through the application in the coal mine site, it is proved that the prediction index and critical value obtained by this method are effective, and can be directly used in the field coal roadway prediction.