The invention provides an antibacterial aluminum alloy material and a preparation method thereof. The antibacterial aluminum alloy material is composed of the following components by weight percentage: 2.3-3.4% copper, 0.5-1.2% manganese, 0.3-0.5% Cobalt, 0.5-1.1% magnesium, 0.13-0.25% samarium, 0.08-0.14% ytterbium, 0.22-0.34% gadolinium, 0.15-0.36% silver, 0.12-0.32% nickel, 0.5-0.9% titanium , 0.28-0.50% zirconium, 0.15-0.27% molybdenum, 0.08-0.2% scandium, 1.2-2.6% silicon, and the rest is aluminum and a small amount of unavoidable impurities. In the present invention, by adding samarium, ytterbium, gadolinium, and silver into the aluminum alloy material, the antibacterial performance of the aluminum alloy material is improved, and the growth of bacteria is inhibited; the aluminum alloy material is improved by adding zirconium and molybdenum to the aluminum alloy material. The strength and plasticity of the material, and adding cobalt and scandium to the aluminum alloy material can effectively overcome casting cracks, improve the quality of the aluminum alloy, and increase the cost rate of the aluminum alloy product. According to the experimental results, the antibacterial rate of aluminum alloy products is above 99.999%, the hardness is above 88HRA, the strength is above 552MPa, the elongation rate is above 8.1%, and the pass rate of flaw detection is above 99%.