Based on gas geology analysis,the geological data qualification method and calculation formula of the permeability of wall rock of coal bed,the complex degree of fault,the complex degree of drape distortion,the complex degree of coal bed inclination angle,roof lithology and the development degree of tectonically deformed coals were put forward.The gas geology index affecting gas emission of No.2 coal bed in Taoer mine were screened out with factor analysis method and three major factors were identified,a prediction model of coal gas emission quantity was established.The theory and practice verifies that the model has higher precision,can is used in the forecast of gas emission in unmined area of Taoer mine.