Provided is a method for producing a boron nitride nanotube-reinforced aluminum composite casting, the method being capable of reducing cost. The method for producing a boron nitride nanotube-reinforced aluminum composite casting comprises the steps of: (a) mixing boron nitride nanotubes and a first aluminum matrix and then pelletizing the resulting mixture; (b) heating and subjecting pellets obtained in step (a) to melt mixing to obtain a melt; (c) cooling and solidifying the melt obtained in step (b) to obtain a master batch; and (d) subjecting the master batch obtained in step (c) and the second aluminum matrix to melt mixing, and then cooling and solidifying the resulting mixture.