The present invention discloses a rare earth-containing amorphous / nanocrystal aluminum anode composite material, a preparation method and an aluminum air battery, and belongs to the techncial field of air batteries. The aluminum anode composite material comprises, by weight, 0.5-5% of Mg, 0.02-2% of Sn, 0.02-2% of Ga, 0.1-5% of La or Ce, and the balance of Al. According to the present invention, aluminum with the purity of more than or equal to 99.8% is adopted as the base, the trae amounts of Mg, Sn, Ga and the rare earth element La or Ce are added so as to reduce the self-corrosion rate and improve the electrochemical property and the surface dissolution uniformity of the alloy, especially the trae amount of the rare earth element is added to the aluminum alloy, and the addition of the rare earth element to the aluminum has effects of oxygen removing, hydrogen removing, desulfuration, melting rate accelerating, metal burning loss reducing, change of species distribution and refinement modification of iron and other harmful impurities, and the like so as to slow down the self-corrosion of the aluminum alloy, such that the anode utilization rate is improved.