The paper introduces the handling methods of CFG pile in local ground treatment of large oil tank through engineering practice, which not only improve the strength of soft ground effectively, but also utmostly keep the coordination of different ground deformation. In view of the specialty of the tank shape, along the tank of the circle loop piles are adopted and the scheme of unequally spaced piles are adopted according to the vertical and horizontal differences of subsoil properties of different sections. The treatment effect of composite foundation is ideal and achieves the desired design goal. It provides a new design concept for the ground treatment of similar projects and could be a reference.