The present disclosure relates to the field of negative electrode materials, and provides a negative electrode material and a preparation method therefor, and a lithium ion battery. The negative electrode material comprises an aggregate, the aggregate comprising an active substance and a carbon material. The mass percentage of the active substance in the aggregate gradually decreases from the center to the surface of the aggregate. The negative electrode material provided by the present disclosure can effectively suppress volume expansion of the negative electrode material and improve battery cycle performance.