Abstract: In view of problems of existing coal and gas outburst risk evaluation models or methods that it is difficult to take into account the uncertainty and ambiguity of evaluation indicators, and the index weights are unreasonable, coal and gas outburst risk evaluation index system is constructed which takes 4 types of factors including coal seam physical properties as secondary indicators, and takes 24 factors including gas emission indicators as three -level indicators. Coal and gas outburst risk evaluation based on cloud model and D -S theory was proposed. Evaluation index is converted from qualitative to quantitative through forward cloud generator of cloud model, and the conflict between evaluation indexes is eliminated through evidence synthesis rule of D -S theory to determine reasonable index weights. Engineering application results show that the evaluation results of the coal and gas outburst risk evaluation based on cloud model and D -S theory are in line with engineering reality and have high accuracy.