The invention relates to the technical field of aluminum alloy, in particular to an aluminum alloy dyeing additive and a dyeing method. The aluminum alloy dyeing additive comprises the following raw materials of, by weight, 30-35 parts of nickel sulfate, 8-12 parts of stannous sulfate, 18-22 parts of sulfuric acid, 16-20 parts of a coloring stabilizer and 13-18 parts of a synergist. The dyeing additive is used for aluminum alloy dyeing, the dyeing efficiency and uniformity can be improved, the dyeing effect and the product yield are improved, the problems of color flowing, different colors andthe like in the dyeing process are solved, the service life of coloring liquid is prolonged, and aluminum alloy has a good appearance effect, good durability and long service life. An aluminum alloydyeing pretreatment method using the aluminum alloy dyeing pretreatment agent is simple and convenient to operate and easy to control, the dyeing efficiency and uniformity can be remarkably improved,the dyeing effect and the product yield are improved, an aluminum alloy dyeing workpiece with a uniform color and a good appearance effect can be obtained, and the aluminum alloy dyeing pretreatment method is suitable for industrial mass production.