Abstract: In order to solve the problem of gas overshoot in the working face during the mining of the upper protective layer of a coal mine in northwest China, the directional drilling technique of gas extraction with downhole pressure relief was put forward. Introduces the selection of equipment and tools, the design method of drilling hole and the control of drilling track, and studies six key technologies of directional drilling construction, such as large angle hole opening, stable grouting solid pipe, mixed drilling, formation discrimination, rapid revolving through abnormal area and reserved branch point. The engineering test results show that the technology has advantages such as high success rate of hole opening, fast penetration through the hole area of broken rock, accurate formation identification, high drilling efficiency, flexible trajectory adjustmssent and reducing construction blind area. The gas extraction concentration of directional drilling is 35.7% on average, which solves the problem of poor extraction effect of conventional drilling, improves the utilization ratio of free gas extraction from the coal seam under pressure relief, and provides technical support for the scientific conception of gas extraction, coal and gas joint extraction in pressure relief mining.