The invention discloses an antibacterial and mouldproof aluminum alloy chromium-free passivation agent. The antibacterial and mouldproof aluminum alloy chromium-free passivation agent is prepared by the following raw materials in parts by weight: 5-10 of 30-40% hexafluorotitanic acid, 5-10 of 40-45% hexafluorozirconic acid, 0.1-0.2 of borax, 1-2 of sodium fluoride, 1-2 of 65-70% nitric acid, 0.5-1 of coconut diethanolamide, 1-2 of sodium benzoate, 0.3-0.5 of chitosan, 5-10 of ethylenediaminetetraacetic acid disodium salt, 50-100 of film coalescing aid, and 800-1000 of water. The aluminum alloy passivation agent can form a compact film having a netty structure on the surface of an aluminum alloy, is excellent in strength, toughness, adhesive ability and corrosion resistance, has antibacterial and mouldproof effects, can prevent the moulding of the aluminum alloy to guarantee the surface smoothness and the color durability of the aluminum alloy, can reduce the environmental pollution, and is excellent in economic benefit and social benefit.