φ219.1/168.3mm large diameter reverse circulation drilling tool is independently developed by Coalfield Geology Bureau of Henan Province, which has been successfully applied to large diameter engineering well with good results. In this paper, the preliminary analysis is made on various factors affecting air-lift reverse circulation drilling efficiency based on the basic production test data, it is concluded that the drilling rate has certain relevance to sinking ratio and air volume, but with little relationship to air pressure.