The stratum is complicated in Dabaoshan molybdenum mine. Leakage， block falling， borehole collapsing and diameter shrinkage often occurred and coring was difficult for drilling tool breaking， sticking， bit burning and burying. By selection of rational drilling technologies， wall protection and leakage control methods and drilling coring methods， the detailed survey and prospecting drilling were smoothly completed. The paper introduced the drilling technology in the complex formation of Dabaoshan molybdenum mine.