The Shenjiayao-Huluyu gold mining area in Shan county， Henan province， is a national forest reserve. For drilling in this area， it is necessary to avoid complex zones and green areas， and green exploration must be carried out to reduce damage to the forest environment； thus， most holes are designed at slant holes. however， due to the large angle of stratum penetration and a large number of weak interlayers， the borehole curvature is not easy to control， resulting in abandonment of the early drilled boreholes because of over-standard curvature. Taking ZKS004 borehole as an example， this paper introduces in detail the borehole drilling technology， the control and prevention of borehole curvature and the measures of deviation correction.