A conveying screw for a food waste disposal device that can stir, crush and cut food waste generated from homes or restaurants, while transferring the food waste, to reduce the amount of the food waste, includes a rotational shaft, and a plurality of spiral rotor blades installed to an outer peripheral surface of the rotational shaft in a spiral pattern to stir, crush and cut food waste. Each of the rotor blades is provided with a plurality of air supply holes penetrating the rotor blade to supply external air to the food waste between the opposite rotor blades, thereby generating bubbles from the food waste and then discharging vapor.