Abstract: The paper introduced the design idea and basis for the series development of the directional drilling rig and the basic performance parameters and the m ain structure features of the ZDY crawler mode directional drilling rig.In combination with the deposition conditions of the rock and coal in the underground mine and the features of the long distance gas drainage directional borehole required for the high accurate tracing in the construction,the paper concluded the major functions of the matched between the directional drilling rig and the directional drilling technique.The paper in detail stated the general layout,hydraulic system,safety protection,key str ucture optimized design of the parts and key technology problems.The analysis on the typical production applied cases approved that the ZDY series crawler mode dire ctional drilling rig could well and fully meet the actual production requirements.