The western area of Zhen’an， South Qinling， is a key area for molybdenum tungsten polymetallic prospecting. Most of the strata in this area are limestone and dolomite. The topographic is large， the terrain is steep， and the karst is developed. There are many karst caves encountered in the drilling construction process. The structure is very developed. There are many fault tectonic belts drilled， the local cores are broken， and the collapse blocks in the holes are strict. Heavy， deep hole construction is more difficult. During the construction process， by optimizing the drilling parameters， taking various leakage plugging measures to fill the karst cave， allocating flushing to deal with the collapse and falling blocks in the hole， adjusting the density of flushing to deal with deep water inrush， solving many construction problems such as difficulty in adopting the core of the tectonic zone， and improving the drilling efficiency. The ZK5201 hole found the skarn-type tungsten mineralization belt and the Indo-Yanshan period granite hidden rock mass. The drilling construction task is successfully completed. The green exploration method is adopted to ensure that the drilling construction site and surrounding water bodies are not polluted， and provide reliable experience for the construction of the same type of deep hole drilling in the area in the future.