The research is made on the application of air DTH hammer drilling technology for geothermal wells in the carbonate formation of Guizhou Province．In a well section of 10-1100m in depth with 216-406mm in diameter, cracks and fractures develop; water gushing, air leakage, block falling and difficult slag discharge frequently occur. In this paper, the DTH hammer equipment configuration, bottom hole assembly and drilling parameters in such complicated conditions are discussed; common problems in the drilling process with air DTH hammer drilling technology are analyzed and the corresponding technical measures are put forward. This paper also summarizes the drilling efficiency and economic benefit of air DTH hammer used for deep well drilling in the complex conditions of carbonate formation. The study results show that by reasonable equipment configuration and technical measures, the drilling efficiency of air DTH hammer can be effectively improved, which is great beneficial to deep geothermal wells of Guizhou Province.