A reactive dye compound and a preparation method and application thereof are disclosed. The dye compound has a structure as shown in a formula (I), wherein D1 and D2 are each independently representedby formulas (a), (b) and (c), and D1 and D2 are not represented by the formula (a) at the same time; R1, R2, R4, R5, R7 and R8 are independently H, C1-C4 alkyl, C1-C4 alkoxy or a sulfonic acid group,m is equal to 0-3, and each R3 is independently selected from amino, a sulfonic acid group, ureido, C1-C4 alkyl, C1-C4 alkyl acylamino or C1-C4 alkoxy; n is equal to 0-3, and each R6 is independentlyselected from hydroxy, amino or a sulfonic acid group; X1, X2 and X3 are independently H, C1-C4 alkyl, C1-C4 alkoxy, -SO2Y1, -NHCO(CH2)pSO2Y2 or -CONH(CH2)qSO2Y3, and at least one of D1 and D2 is a fiber-containing active group, and Y1 to Y3 are each independently -CH=CH2, -C2H4OSO3H or -CH2CH2Cl, p and q are equal to 1-3. The invention provides the application of the dye compound in printing anddyeing of cellulose fibers, polyamide fibers and fabrics of the cellulose fibers and polyamide fibers, has good fixing rate, good washing fastness, good lifting force and good fiber bonding stabilitywith fibers.