Air DTH hammer drilling technology can not only improve drilling efficiency， but also does not damage geothermal reservoirs； therefore， it is widely used in geothermal well drilling. However， it is limited by drilling depth and water output. During drilling of deep geothermal wells in the Shunhuang Mountain of Yongzhou， Hunan， air down-the-hole hammer drilling technology was used to achieve a breakthrough in the drilling depth with the drilling depth up to 1820m， and the actual water output of 400m³/day at surface temperature of 43℃， meeting the design index. The relevant drilling measures are summarized so as to promote application of the technology in geothermal deep wells.