This paper introduces the drilling fluids and lost circulation control technology applied in Jinchang gold mine, and takes an example of diamond wire-line coring drilling well (ZK-0003) to illustrate the high efficiency, low cost and stable hole wall. The drilling fluid system had good effect of caving prevention and lost control with strong adaptability and suitable viscosity; the formed thin mud-cake was dense and tough, with which low carrying capability and serious water loss were solved in small diameter wire-line coring drilling.