Abstract: Combined coal mine directional drilling technology features, design principles and fixed parameter principles including depth, azimuth and dip angle of directional boreholes are introduced in this paper. According to the research of mathematical principles of directional borehole trajectory calculation, the paper summed up the drawing and calculating two kinds of drilling trajectory design and calculation methods, which were applied in 27 coalmine areas. The deepest directional drilling depth is 1 212 m.