Caomiao area of Pengyang County is one of important sites of deep coal resource exploration at mountainous area of southern Ningxia. Lost circulation is very common during drilling, which induces borehole accident and mechanical failure, even leads to abandonment of the borehole. Analysis was made on countermeasures for leakage protection and sealing in different formations, and corresponding formulas and operating details were obtained through laboratory tests. Field tests were also made with representative of ZK7-1; it is showed the lost circulation was controlled effectively, the leakage protection and sealing technology could be popularized in similar geological condition.