SU77-5-8H is the first horizontal well crossing coal seam with high-inclination, by which development benefit was promoted for Shansi group23 in Su77 block of Sulige gas field. The upper part of target bed (Shanxi23) is structured by carbonaceous mudstone and cola seam in the thickness of 20～30 meters. Because of the specialty of coal-bearing stratum, collapsing occurs easily in drilling process, and this coal-bearing stratum is in deviation building section in front of target point with big construction difficulty and high risk. Analysis was made on the main technical points, and introduction was made on the safety technology about design optimization, trajectory control, construction measures and drilling fluid technique.