Abstract: In order to solve the problems of short length of drilling through coal, uncontrollable drilling track and low effective utilization rate of borehole for gas extraction with floor through beds borehole in thin outburst coal seam, long distance drilling is carried out in coal seam floor strata by using comb directional drilling technology of floor to control gas outburst in thin coal seam. According to the construction characteristics of the comb directional drilling of the bottom plate, the key technologies such as the location selection of the branch points of the comb directional drilling of the bottom plate, the determination of the spacing of the branch holes, the construction technology of the opening of the branch holes and the control of the drilling track are analyzed, and some suggestions are given. Practice has proved that the application of the comb directional drilling technology of the bottom plate can make the comb directional drilling of the bottom plate realize the effective coverage of thin outburst coal seam in the range of more than 500 m and greatly improve the utilization rate of the drilling.