The invention discloses a water-based coloring layer coating for a transfer film and a preparation method of the water-based coloring layer coating and particularly relates to a pure water-based coloring layer coating for a heat transfer film (alumite). The coating is prepared from, by mass, 20-60 parts of styrene-maleic anhydride polymerized resin water solution, 20-50 parts of polyacrylic resin water solution, 3-10 parts of water-based reinforced resin, 0-3 parts of water-based cross-linking agent, 0-1 part of water-based wetting leveling agent, 0-1 part of water-based defoamer, 0-1 part of PH modifier and 0-30 parts of deionized water. The styrene-maleic anhydride polymerized resin water solution and the polyacrylic resin water solution are prepared through a hydrothermal alkali dissolution method, and the product is prepared through a stirring and mixing method according to a feeding sequence. The product is purely based on water, environmentally friendly and safe, and can completely replace similar solvent type products on the market, and various properties are qualified through detection.