The invention provides a novel cathode material for a lithium ion battery and a preparation method thereof. The material is compounded by natural graphite, oil coke and pitch. The compound process comprises mixing, pinching, rolling sheets, smashing, forming, carbonizing, graphitizing, spherizing and the like. By weight, the natural graphite is 35 to 55 parts, the oil coke is 25 to 45 parts, and the pitch is 15 to 25 parts. Compared with the prior art, the cathode material has the advantages of synthetic graphite and natural graphite and is large in volume, high in first efficiency and circulation efficiency and excellent in charging and discharging performance. Furthermore, the natural graphite adopts secondary products discharged and collected by a dust remover after natural crystalline flake graphite is smashed in spherical mode. Thus, secondary products are reasonably used, and production cost is remarkably reduced.