CGGC overcame great difficulties in Geheyan, TGP, Ertan, Dachaoshan, Laxiwa underground works construction, created new record in the world and Asia. Ertan underground powerhouse was the largest powerhouse in Asia then. Tail-water surge chamber of Dachaoshan Hydropower Station was the largest underground chamber in Asia then. TGP underground powerhouse is the highest and widest one in the world now.