Abstract: In order to improve the depth of gas extraction drillings and increase the footage of borehole in soft coal seam, taking advantage of the controllable drilling trajectory of directional drilling technology, good results were obtained by optimizing the arrangement of directional drilling and adopting the flushing fluid for directional drilling. The test drilling depth is more than 700 m, and the continuous footage in coal is more than 400 m, which to some extent improves the depth of gas extraction and footage in soft coal seam. It also has better application and promotion value for the directional drilling technology in the soft coal seam gas extraction drilling construction.