Abstract: There are some shortcomings in the split drilling rig and the entire crawler drilling rig，that can not integrate such functions as high flexibility，small size，high personnel security into one device.So the drilling efficiency for gas extraction is lowered and the drilling rig has a poor adaptability under complex drilling field and mines.The split crawler drilling rig is a new type of drilling and construction equipment for gas extraction.Due to its split and crawler structure，this new-type rig owns small size，flexible underground mobility，and workers can stay away from the orifice and the host to realize control and operation of drilling.Combined with complex conditions of coal mine/rock occurrence and drilling field，and based on analysis and investigation of the structural features，the main function，the key technologies and the hydraulic systems of split crawler drilling rig，the split crawler rig series for different condition and construction environment were designed.The industrial test showed that the split crawler rig has moderate dimensions，high flexibility at underground，high comprehensive drilling efficiency，and wide adaptability.It has a good prospect in mines with complex conditions.

Key words: Coal mine, Split-type crawler drilling rig, Gas drainage, Hydraulic system