Abstract: In order to solve the engineering problem that it is difficult to determine the layout level of top pumping roadway in 3111 mining area of Xinjing Coal Mine, the numerical software FLUENT is used to explore the distribution characteristics of stope gas volume fraction under different vertical strata (48,53,58 m from coal seam) and different horizontal strata (43 m, 48 m, 53 m from return air roadway). And carry out the engineering verification. The results show that the overlimit problem of gas in stope can be effectively controlled by roof pumping. Under the condition of vertical horizon variation, the extraction range and extraction effect are mutually exclusive. The reasonable parameters of 53 m away from coal seam and 48 m away from return air roadway are suitable for the top pumping roadway in 3111 mining area. The monitoring results show that the fracture of the basic roof will lead to the large-scale development of fracture zone and gas leakage phenomenon, resulting in the decrease of gas volume fraction in the roof pumping roadway, and the increase of gas volume fraction in the upper corner and return air roadway. In the subsequent cycle pressure process, similar characteristics will still be shown, but the gas volume fraction in the upper corner and return air roadway shows a decreasing trend with the continuous advance of the working face.