The invention relates to a three-color key injection molding technology. The technology comprises the steps in sequence of S1, opening a mold for the first time; S2, installing the mold; S3, closing the mold for the first time; S4, carrying out first color injection molding; S5, opening the mold and closing the mold for the second time; S6, carrying out second color and third color injection molding; S7, carrying out discharging; S8, carrying out subsequent processing; S9, carrying out paint spraying and laser engraving; and S10, installing a light guide body. The three-color key injection molding technology has the advantages that the yield is high, the production efficiency is high, a second color and a third color of a product are well fused, the waterproof and dustproof effects are good, the appearance is attractive, and the using effect is excellent.