The invention discloses a three-dimensional spherical silicon-carbon composite negative electrode material and a preparation method therefor, and belongs to the field of the lithium ion battery negative electrode material. The composite negative electrode material consists of graphite, silicon and amorphous state carbon, wherein graphite and silicon are coated in the amorphous state carbon. The preparation method comprises the steps of dispersing nanometer silicon and a carbon source into an organic solvent, performing spray drying to obtain a Si@C precursor, and performing carbonization to obtain a Si@C material, wherein the volume expansion effect of silicon can be effectively relieved by the surface carbon layer; and next, dispersing the Si@C material, graphite and the carbon source into the organic solvent, performing spray drying to obtain a silicon-carbon composite negative electrode material precursor, and performing carbonization to obtain the three-dimensional spherical silicon-carbon composite negative electrode material. By virtue of the dual-layer amorphous state carbon layers, the volume expansion effect of silicon in the charge-discharge process can be effectively relieved; the amorphous state carbon layer on the outer layer has small specific surface area, so that high irreversible capacity loss is avoided; and therefore, the obtained material has relatively high specific capacity and initial efficiency and excellent cycling stability.