Abstract: In order to master the distribution law of negative pressure in the bedding long borehole, and better guide the determination of key parameters of bedding borehole and the application of drainage technology, the gas flow model in coal around borehole was established, and it was coupled with the gas flow model in the borehole, the formula for calculating the negative pressure distribution in the bedding borehole was obtained. The distribution of negative pressure in the borehole and the extraction effect under three processes were analyzed theoretically, and the three processes were traditional extraction technology, lengthening extraction tube technology and loading the screen pipe technology. The field test was carried out in N3702 working face of Yuyang Coal Mine of Chongqing Energy Investment Group. The results show that the theoretical calculation formula is used to fit the measured data, and the fitting degree is close to 1, the pressure loss deviation between the calculation value and the measured value of 100 meters drilling hole is only 3.97%, and the calculation model can meet the need of precision in engineering practice; the comparison of the effects of the three extraction processes shows that the traditional extraction process has large pressure loss and is prone to air leakage, in the hard coal seam with good hole forming conditions, lengthening extraction tube technology should be adopted, while in the soft coal seam with poor hole forming conditions, loading the screen pipe technology should be adopted.