The detailed survey of Xianrenyan gold deposit in Changning City of Hunan Province is a focus scientific research project for Hunan Province Nonferrous Metal Geological Survey Bureau. Because of the high rock hardness, frequent changes of soft and hard formations, groundwater, karst caves, old complex galleries and some other reasons in this mining area, the construction is difficult with low drilling efficiency and core recovery rate is difficult to reach the standard. In order to solve this problem, through repeated tests and research, the improvement of flushing fluid and plugging technologies have been made and the mud system and plugging measures suitable for the construction in this area are developed. Some achievements have been received in complex formation drilling in Xianrenyan mining area.