Xin'an mine has extremely developed geological structures and complex hydrogeological conditions, especially in the area of the -500 north flank of the mine, where two ash water emergencies occurred during the mining activities in 2010 and 2011, resulting in the suspension of production by flooding. The mine is prone to water damage accidents when the structure is not identified. At the same time, Xin'an mine was characterized by complex hydrogeological conditions, high water gush and high water pressure, and there were great safety hazards in exploring the structure underground. It was proved that the horizontal directional drilling technology was used to accurately investigate the structural conditions in the area.