The invention relates to the technical field of a paint, and concretely discloses a vehicle multifunctional aqueous paint and a preparation method thereof. The vehicle multifunctional aqueous paint comprises the following components in parts by weight: 15-25 parts of an aqueous polyethersulfone dispersing emulsion, 25-30 parts of an aqueous hydroxy acrylic emulsion, 5-7 parts of a curing agent, 1-5 parts of organic silicone powder, 1-5 parts of nano alumina, 0.05-0.5 parts of nano titanium dioxide, 1-8 parts of a pigment, 3-10 parts of a fire retardant, 0.05-0.5 parts of nano zinc oxide, 0.1-1part of fluorescent powder, 0.1-0.2 parts of a pH conditioning agent, 0.1-0.2 parts of an antifoaming agent, 2-5 parts of a film-forming auxiliary agent, 0.3-0.5 parts of a dispersant, 0.3-0.5 partsof a base material wetting agent, 0.5-1.0 parts of a thickening agent, 2-3 parts of a cosolvent, and 5-10 parts of deionized water. The vehicle multifunctional aqueous paint is a normal-temperature air-drying coating, has the advantages of excellent anti-corrosive property, safety and no toxicity, and convenient construction, has fluorescent effect and fireproof effect, protects the metal base material and increases the work security, and is especially suitable for special vehicles such as a large-scale outdoor work vehicle which is not suitable for baking.