To construct a building in some special geological structure conditions, the key point of finishing the project successfully is how to choose the foundation type or the method of the foundation treatment. In this article, through a foundation treatment in Beijing which adopted artificial dig-hole and expanded bottom perfusion CFG pile in engineering practice, introduced design calculations, construction technology, reinforcement mechanism and scope of application of this kind of pile, to provide a useful reference for similar engineering design and construction of foundation treatment in Beijing.