The paper introduced composition and on-line method, main functions and characteristics of CUG-2 drilling monitor with high precision and its application in ZK43-1 deep hole in Rushan of Shandong province. The practical application showed that CUG-2 drilling monitor with high precision can not only real-timely monitor, display and store drilling parameters, but also have some significant advantages such as forecasting hole accident and data wireless transmission, which has wide application prospect.