Abstract: Provided are methods for preparing a nickel-cobalt-aluminum precursor material and a cathode material with a gradient distribution of aluminum element. The precursor material and the cathode material based on the precursor material prepared by the methods are of sphere or sphere-like shapes in which the distribution of the aluminum element is changed in a gradient manner, and the particle size distribution is uniform. The synthesized material has a high tap density, is not sensitive to ambient carbon dioxide and moisture, and has a good processability, a high specific capacity and a good stability property.