Based on the problems of uncontrollable drilling trajectory, shallow drilling depth and low proportion of effective drilling strata for water exploration and drainage during roadway excavation, Xingdong Mine innovatively adopted underground directional drilling technology according to the construction experience of ground directional drilling. And aiming at the difficulty of directional drilling hole forming in complex strata, the technical measures including grouting to reinforce broken strata, reaming technology to dredge drilling, and rapid passage of broken strata were adopted to effectively solve the problem of hole forming. By analyzing the lithologic characteristics of different depths of coal seam floor strata, the construction technology of ' directional guide hole and reaming hole ' was created, and the efficient drilling of directional deep hole was realized.