Modified anode material and preparation method thereof as well as lithium ion battery

The invention provides a preparation method of a modified anode material. The preparation method comprises the following steps: stirring an anode material and a hydroxyl alumina sol in water for reacting, and drying by distillation to obtain a powder product; roasting the powder product to obtain the modified anode material. According to the preparation method of the modified anode material, the hydroxyl alumina sol is adopted as an aluminum source to perform water cladding on the anode material; compared with the prior art that alumina is adopted to perform surface cladding on the anode material, the preparation method has the advantages that the attenuation of the cycle performance of the anode material caused by lithium loss due to water cladding cannot occur, the contact area between the anode material and electrolyte can be effectively reduced, the dissolving of the anode material in a high temperature cycling process is improved, and the cycling capacity keeping capability is enhanced; therefore, a lithium ion battery prepared by the modified anode material which is prepared by the method has better cycling performance and high temperature storage performance. The invention also provides the modified anode material and the lithium ion battery.