Abstract: According to the disaster system theory and risk theory, combined with the characteristics of coal mine gas explosion, the disaster risk assessment index system about coal mine gas explosion which is composed of the hazard-formative environment, hazard-caused factor and hazard-bearing bodies three subsystems is established. By analyzing the data of gas explosion accidents from 2002 to 2012, rough set attribute reduction method is used to determine coal mine gas explosion hazard risk index system.