A long concrete core sample with a diameter of 250 mm and a length of 26.5 m was taken from the 15 dam section at an elevation of 1 693.8 m in TB Hydropower Project. The core sample was intact, with a smooth and dense surface and good interlayer bonding. Based on the actual situation of drilling, research was conducted on the selection of drilling machines, material processing requirements, drilling process control, and other construction techniques during the construction process of the concrete long core. The results indicate that GQ-60 engineering drilling rig was selected for the construction process. The roller compacted concrete within the core range adopts inclined layer rolling construction technique. During the coring construction process, the same drill bit and reamer should be used, and the hardness of the drill bit body should match the strength of the concrete, which should meet the construction requirements.