Abstract: ZDY6000L(B) type all hydraulic directional drilling rig was designed to meet the demand of gas extraction borehole construction in high gas coal mine, and it has the characteristics of compact layout, wide technological adaptability. Load sensing technology was used in hydraulic system to realize open system with two series connection pumps, and rotation and feeding conditions were improved with good energy-saving. It was validated in field test with high construction efficiency, full function and easy control; design requirements were gained. It can provide equipment for safe and high efficient exploitation.