The present invention discloses a method for preparing a spherical lithium battery cathode material LiNixCoyAl1xyO2 based on normal distribution of aluminum concentration. The morphology of the LiNixCoyAl1xyO2 material prepared by the method is close to a sphere structure, and concentration of an aluminum element is normally distributed from a sphere center to a sphere shell. According to the method disclosed by the present invention, colloid is prepared by combining aluminum ions and hydroxy radicals, colloidal particles are dissolved under the action of strong base to form tetrahydroxy meta-aluminic acid radical ionic liquid. Precipitation is completed in a manner that tetrahydroxy meta-aluminic acid radicals are hydrolyzed to generate aluminum hydroxide, coprecipitation of the aluminum hydroxide and nickle and cobalt hydroxide can be implemented due to a low hydrolysis rate, and the hydrolysis rate of the aluminum hydroxide is controlled by PH, and the LiNixCoyAl1xyO2 spherical material of which aliminum concentration is normally distributed is formed. By the means of the dispersing effect of an organic medium 3-methyl-1-butanol, mixing of a lithium source and precursor particles at the molecule level is implemented under the heating condition and capacity per gram and cycling performance of the cathode material are greatly improved.