The invention belongs to the field of lithium ion batteries and discloses a method for preparing an anode material. The method comprises: ball-milling the precursor of the anode material in an atmosphere of sulfur dioxide; and sintering at high temperature in atmosphere of oxygen. In the method for preparing the anode material, the doping of the sulfur element is more uniform, the overall performance of the material is higher, and particularly the specific capacity and cycle index of the batteries are improved considerably. The method also has the characteristics of safety, reliability and nohidden danger.