The invention discloses a dispersing bright blue dye compound which comprises a component A, a component B, a component C and a component D, wherein the component A is the compound shown as formula (I); the component B is one or two of the compounds shown as formulas (II-1)-(II-2); the component C is the compound shown as formula (III); the component D is at least one of the compounds shown as formulas (IV-1)-(IV-6). The invention further provides a dispersing bright blue dye product which contains the dispersing bright blue dye compound and an additive. The invention also provides an application of the dispersing bright blue dye product in hydrophobic fiber material dyeing. The dispersing bright blue dye product has the characteristics of sublimation resistance, friction resistance and excellent washing fastness and is especially suitable for the dying of polyester/ammonia elastic fabric with higher requirement for color fastness.