According to the drilling problems in Zhaishang gold mining area of Gansu province, such as structural development, broken formation, thick fault zone, borehole diameter shrinkage, leakage, collapse, low core recovery rate and frequent downhole accidents, plant glue mud, PAB solid-free flushing fluid, multi-layer casing protecting wall technology, drilling tools of the Q series and hydro-efflux wire-line coring drilling tools by local reverse circulation were applied with good results.