To prove the mineral reserves and the occurrence of mineralization belt, wire-ling coring drilling test was made. Because of the complex geological conditions, the used bit was not well adapted to make good drilling results. Through the selection test of impregnated diamond bit and the drilling track, analysis was made on the impact of horizontal drilling on the bit. Based on the borehole track, reverse analysis was made on the relationship of horizontal drilling and borehole track, suitable bit for the mine geological conditions was selected with improvement methods and suggestions on preventing hole bending put forward.