Abstract: Dafosi Minefield is located in the southern part of Binchang Mines. According to the exploration drilling,the gas content of the coal seam is low, however, the coal seam is thicker with rich CBM resources, which has high mining and utilization value. In order to clarify the storage characteristics of CBM reservoir in minefield and reasonable guidance for effective mining, taking the No.4 coal seam of Dafosi Minefield as an example, by analyzing the correlation between the local quality factors and the gas content of parameter wells, the gas content affecting the No. 4 coal seam is determined. Then based on the idea of fuzzy comprehensive evaluation of the evaluation system was established. Finally, data processing and overlay analysis are achieved under the MapGIS platform and the prediction of the favorable coalbed methane resources in the No.4 coal seam of Dafosi Minefield is completed. The research results show that the main controlling factors affecting the gas content of No.4 coal seam in Dafosi Minefield are: coal seam thickness, buried depth, degenerative degree and thickness of mudstone in upper and lower Yan'an Formation. The most favorable areas, favorable areas, more favorable areas, unfavorable areas and the most unfavorable areas for coalbed methane storage accounted for 8%, 30%, 40%, 17%, and 5% of the minefield, respectively.