Gas Pressure is the driving force of gas emission and prominent, but also calibration parameters. Accurate determination of coal seam gas pressure on the rational and effective development of the mine to prevent gas measures, forecasting coal and gas outburst risk of important and commonly used in coal seam gas pressure measurement techniques, mostly in the sealing segments rock was very hard and dense conditions, but due to restrictions by the sealing material on the case of soft sandstone or drilling around the micro-cracks, the sealing effect is not ideal, easy to leak, so that the measured out of the gas pressure value lower than the true coal seam gas pressure, this will lead to a wrong judgment, resulting in potential accidents.