The invention relates to an aqueous metal glossy lacquer for cars and a preparation method of the aqueous metal glossy lacquer for cars. The aqueous metal glossy lacquer is prepared from the following ingredients in percentages by weight: 10-15% of aqueous acrylic resin, 10-15% of aqueous acrylic acid emulsion, 6-12% of aqueous polyurethane dispersion, 1-3% of aqueous amino resin, 1-5% of anti-settling agent, 5-10% of aqueous aluminum powder, 4-6% of pH (Potential of Hydrogen) regulator, 0.6-2% of auxiliary, 4-10% of cosolvent and 30-50% of deionized water, wherein the sum of all the above ingredients is 100%. The preparation method of the lacquer is convenient to operate and capable of ensuring product quality. The preparation method of the lacquer is convenient to operate, and the quality of a product can be ensured. Compared with the prior art, the aqueous metal glossy lacquer provided by the invention has the characteristics of quick drying, coating repeatability, environmental friendliness, safety and certain metal texture, and is mainly applied to a car original lacquer. The 3C1B process can be used; therefore, fixed-asset investment is reduced, energy consumption is reduced, and the capacity and yield of a car production line are improved.