The invention discloses dark red reactive dye and a preparation method thereof. The dark red reactive dye is one material selected from general formulas of the formula (I) or is a mixture obtained through compounding two or more structures selected from the general formulas of the formula (I) according to any proportion. One material shown by the formula (I) is selected from any one of materials of the following structure general formulas or is a mixture of two or more materials of the structural general formulas, wherein R1, R2, R3 and R4 in the formula (I) respectively and independently represent -H, -CH3, -OCH3 or -SO3M; Y1 and Y2 respectively and independently represent -CH=CH2 or -C2H4OSO3M; M represents hydrogen or alkali metal. The dark red reactive dye has the advantages that the lifting performance is good; the friction firmness, the water washing firmness, the light fastness and the heat stability are high. The formula (I) is shown as the accompanying drawing.