Abstract: It's described that the design concept and construction process of a building pit which sites in Luanda,the capital of Angolan. The example shows that structure surface area and building site area ratio 92.5% by the combination of nail and anchor supporting structure. Utilizing the feature of the pit side soil appropriately, the pit excavation depth is more than 14m with vertical slop, and has little no dangerous on normal function and structural safety of dwelling houses which is from the pit at the edge of 0.3~0.5m.The maximum horizontal displacement of the pit can be observed is less than 3mm, The supporting structure endured repeated heavy rains, and its safe periods are past 2 years.