Abstract: In order to solve the drilling difficulty and poor borehole forming of the gas drainage borehole in the soft seam, the gas drainage technology by long directional borehole in floor soft seam is presented. The suitable stratum in the protected coal seam floor is selected, using directional drilling to drill a directional long main borehole in the selected stratum, and many branch holes from the main borehole is drilled toward the coal, so the gas is extracted from the pressure-relief coal seam. The depth of two main holes is up to 603 m in field trial, and the cumulative value of pure methane drainage volume is up to 183 204.98 m³. The engineering practice shows that the technology not only avoids the hole drilling difficult in the soft coal, but also achieves regional gas drainage for the branch hole effectively.