The Coca Codo Sinclair Hydropower Station in Ecuador, located in the tropical rain forest area, adjacent to an active volcano, is the largest hydropower station in the country. Considering the complex natural conditions such as heavy sediment load, high seismic intensity, deep overburden, and long water transfer distance and high water head, key technical problems was successfully solved through pioneering design and research, such as: the construction of large-scale sedimentation basin, large structures on ultra-deep overburden, large caverns in volcanic ash, 24.8 km long deep-buried tunnel, penstocks with 618 m water head, large-span underground powerhouse caverns, high-head large-capacity impulse turbines. The innovative design created good conditions for the smooth construction of the project, guaranteed a safe and reliable operation of the project, and opened up new paths for the construction of water conservancy and hydropower projects.