According to the geological characteristics of CBM reservoir in Qinshui region and the technical difficulties in horizontally butted multi-branch wells construction, and combined with the drilling scheme of 2012 ZX-SP-01 well group, this paper introduces the key technologies about the well bore structure of drainage well and engineering well, wellbore trajectory optimization and suspended sidetracking, as well as the determination of the bit position and azimuth to coalbed using azimuth gamma. The real drilling trajectory and the late drainage effects show that by this series of technologies, the successful horizontally butted multi-branch wells construction can be ensured to form mature drilling technology of CBM horizontally butted multi-branch wells for good results.