The recommended designing method in the codes of CFG pile composite foundation for storage tanks is based on the bearing capacity controlling. It has been pointed out that this design method does not consider the actual bearing capacity of soil between piles and that of CFG piles. According to the deformation and stress behaviors of soil between piles and CFG piles in the composite foundation, as well as the characteristic of storage tank foundation, a new settlement controlling design method has been brought forward for the CFG pile composite foundation of storage tanks. According to the relationship of composite foundation settlement, different reinforcing depths and different replacement rates, as well as the allowable settlement value of foundation, an economical and feasible technical plan is determined and the bearing capacity of composite foundation is also checked, achieving a optimal design. The proposed method has been proved to be economical and feasible to the application in practical projects.