: With the increasing demand for mineral resource exploration in recent years, the depth of core drilling and the complexity of strata have been increasing, leading higher requirements for controlling the trajectory of drill holes in order to accurately target the ore bodies and achieve geological objectives. This paper introduces the construction overview of the Z2901 drill hole at the Chang"an gold mine, and addresses a series of technical difficulties such as wall collapse, rock falling, drill breakage accidents,-gauging of drill holes, depth trajectory control, and core sampling in complex strata. It summarizes the experience of construction of large-angle geological core drilling, provides technical references for the construction of large-angle geological core drilling.