The prospecting work for gold deposits in Xiling exploration area has entered the prospecting stage, the grid layout was plotted 80m × 80m with very strict drilling quality requirements: the target deviation in the final completion should be less than 1/4 of the exploration grid, that is not exceeding 20m. For the holes in Xiling exploration area, the designed depth were all more than 1500m, some even more than 2500, which is far beyond the requirements of geological core drilling procedures. Based on many years’ experience in deep hole construction, some breakthroughs have been made in deviation prevention and straightening, drilling tool centralizer is independently developed and a borehole straightening method is originated to form a set of practical drilling quality assurance measures.