Comprehensive evaluation method for judging damage grade of coal and rock mass of coal face

The invention discloses a comprehensive evaluation method for judging the damage grade of a coal-rock mass of a coal face, which comprises the following steps of: firstly, collecting a micro-seismic signal during the stoping period of the coal face, and determining a damage area; according to the collected micro-seismic signals, four micro-seismic indexes in the recovery process of the damaged area are calculated respectively; according to a calculation result, obtaining a judgment result of each micro-seismic index on each damage area; then, according to changes of four index values of the whole stoping stage, weights are given to all microseismic indexes through an entropy weight method; calculating a comprehensive evaluation index psi of the damage area based on the weight and the judgment result of each index in the recovery period of each damage area; finally, the coal rock mass damage grade of each damage area is judged according to the psi value. Therefore, the damage grade of the damage area in front