The formation conditions are quite different in Yechangping mining area; a lot of problems have been exposed in the initial construction by applying the previous successful experience and drilling technologies: the upper block falling and serious sticking cause borehole abandonments; especially in weathered rock sections with strong hydrophily, hole wall collapse, splitting failure on formation by high pump pressure and the formation being damaged by pressure lead drill bit burying. 5 abandoned boreholes cause huge economic loss and seriously affect exploration progress. After the improvement of drilling operation, the drilling hole rate has been significantly raised, 46 holes are completed, and all being fine holes, the deepest drilling depth reaches 1501.54m and efficiency per rig is improved obviously from 130m to 252m. In this paper, analysis is made on drilling method, flushing fluid property and borehole structure, some problems in construction and corresponding causes as well as countermeasures are introduced and construction experience is summarized.