The foundation of the main building of Macao Meigaomei Gold Palace consists of 38 under-reamed bored cast-inplace piles, the diameter of pile hole was enlarged from 3m to 4.2 - 4. 5m in narrow light weathered granite construction field. So Benoto Method, reverse circulation drilling with quadruple-wing drag bits, drilling with roller-type cutting head and combined drilling technology was adopted as well as wall protection with mud, which is strictly districted in Hongkong and Macao. The project became an example for pile hole drilling with mud in Hongkong and Macao, and good economic result was received.