Abstract: Forecast datum of coal seam gas content, as the basis for design of mine ventilation system and coal and gas outburst prevention and control measures, the prediction accuracy of the forecasts will have direct impact on mine ventilation equipments, roadway section, gas extraction equipments and other parameters. Mayi West No.1 Mine is a new mine, 3^# coal seam as the first coal layer, gas content datum are very scarce, so the paper introduces the quantitative theory to study the gas content and geological factors. Compared the results of mathematical geology model predictions with the measured value, the error is smaller, which proves the validity of the method.