Abstract: The Lianghekou Hydropower Station is a national key project and the leading reservoir power station in the middle and lower reaches of the Yalong River Basin. As a landmark project representing China's hydropower development in high-altitude,cold regions,it holds milestone significance in global hydropower construction history. With a maximum dam height of 295 meters,it ranks as the world's second tallest and China's highest rockfill dam,marking a breakthrough in 300-meter-level core-wall rockfill dam construction technology. The project area's complex geological conditions posed major challenges,including active boundary faults,high seismic resistance requirements,stability control of massive reservoir slopes,reinforcement of ultra-high hub slopes,and utilization of multi-source anti-seepage materials. Following its full commissioning on March 18,2022,the station has provided valuable insights for addressing engineering geological challenges in large-scale hydropower projects. The experience gained from its survey,design and construction offers important references for similar ultra-high core-wall rockfill dam projects worldwide.