The invention relates to a nickel cobalt lithium manganate composite cathode material and a preparation method of the nickel cobalt lithium manganate composite cathode material. The nickel cobalt lithium manganate composite cathode material has the chemical formula of Li(NixCoyMn<1-x-y>)O2. The preparation method comprises the steps that after soluble nickel salts, cobalt salts, manganese salts and complexing agents are uniformly mixed, sodium hydroxide precipitating agents are added, the reaction is carried out in a stirring reactor with an ultrasonic device, composite hydroxides of nickel cobalt manganate are obtained, then, the composite hydroxides, water soluble macromolecular compounds and lithium source compounds are placed in the stirring reactor with the ultrasonic device, the spray drying is carried out in the ultrasonic reinforced stirring mixing process, and nickel cobalt lithium manganate precursors are obtained, the precursors are subjected to primary sintering under the certain atmosphere protection, and nickel cobalt lithium manganate products are obtained. When the nickel cobalt lithium manganate composite cathode material and the preparation method are adopted, the prepared product particles are uniform, the morphology is regular, the specific surface area is small, the tap density is high, the electrochemical performance is excellent, the processing performance is good, the cost is low, the environment-friendly effect is realized, and the environment pollution is avoided.