In view of the complex strata conditions at Roof 36-700 in the third mining area of Dongbaowei Coal Mine， as well as the problems such as heavy workload of conventional drilling， insufficient depth of single holes， difficulty in drilling， low concentration of gas drainage， coal mine underground directional drilling equipment was tested to drill large-diameter high-level roof directional holes in complex strata in Dongbaowei Coal Mine. According to the actual geological conditions of the coal seam roof， six ?120mm high-level directional boreholes with 120mm large diameter were drilled in the roof of the 36# coal seam. The completion rate of the holes with a depth more than 300 m reached 83.3%， with the maximum hole depth up to 510m. The gas drainage concentration with large diameter high-level roof directional drilling was 66.7% higher than that with conventional drilling in the original working face， resulting in significant gas extraction effect. The successful application of large-diameter high-level roof directional drilling provides technical support for its promotion and application in Dongbaowei Coal Mine and mining areas with similar conditions.