Abstract: Aiming at features of spiral drilling technology in soft coal seam, a high speed and long stroke crawler drill rig ZDY1450LG has been developed. Key technologies such as closed nitrogen hydraulic chuck, extensional cylinder feeding device, anti-sticking protection function, angle adjustment device, centralizing device of helix drilling rod were stated. The type test and industrial test has verified that the rig can adjust the hole, has simple operation and convenient transportation, key components and the design are reasonable and reliable, improves the drilling performance and efficiency, reduces drilling accidents.