Abstract: The gas pressure measurement device for long distance coal seam with large depression angle is studied, and the highlight is that the design type of “double baffle and slurry pipe”. Through the application of gas pressure measurement device in No.15 coal seam of Qianjin Coal Mine, and compared with the gas pressure data of traditional hole-sealing process of “single baffle and grouting”, the results of three groups of gas pressure test boreholes are, respectively, 0.17 MPa and 0 MPa, 0.25 MPa and 0.25 MPa, 0.27 MPa and 0.18 MPa. The research shows that the hole-sealing process of “single baffle and grouting” is suitable for the short distance hole-sealing, whereas the grouting and hole-sealing device of “double baffle and slurry pipe” has better hole-sealing quality for long distance drilling with large depression angle.