ZK4816 borehole is the first drilling with a depth of 1000 meters implemented in Zhaishang gold deposit area， Min County. For the problems of difficult drilling， wall protection etc. in complex formation of mining area， through the implementation of deep core drilling project， drilling technology research and practice were carried out simultaneously， and technical measures such as GSP drilling fluid， enlarged diameter drilling tools and directional drilling were successfully applied. The drilling depth reached 1172.88m. The wall protection period of GSP drilling fluid was three times longer than that of natural plant gum drilling fluid. Drilling with enlarged diameter drilling tools can form a large annular gap and greatly improve the ability of drilling fluid to carry coarse rock powder. The application of “GSP drilling fluid & enlarged diameter drilling tools” technology effectively ensures the deep hole construction. This paper provides a reference for the next deep core drilling work in complex strata.