The invention discloses a settling, reinforcing and lifting method of independent foundations of an existing building, and belongs to the technical field of building foundation reinforcing and lifting. The settling, reinforcing and lifting method comprises the following steps: S1, settlement survey is conducted, specifically, all the independent foundations are subjected to settlement survey according to datum elevation points set on site, settlement data are recorded, the differential settlement is calculated, and a unified elevation line is set; S2, the foundations are stabilized, specifically, soil bodies at the bottoms of the independent foundations are subjected to grouting reinforcement treatment, and a stable area is formed; and S3, the foundations are lifted, specifically, soil bodies, close to the independent foundations, on the upper part of the stable area are grouted so as to lift the independent foundations to the unified elevation line. The settling, reinforcing and lifting method has the characteristics of high stability, high precision, easy construction and low cost.