The invention provides a black dye composition and dyeing application and method thereof. The black dye composition and the dyeing application and method thereof are used for dyeing of brocade/cotton and brocade/viscose blended fabrics and interlacing fabrics through the one-bath and two-step method. The composition comprises one or more reactive dye compounds shown in the general formula (I), one or more reactive dye compounds shown in the general formula (II) and one or more 1:2 metal complex dye compounds shown in the general formula (III), wherein the dye compounds are mixed in a certain proportion. Fastnesses, especially light fastness and wet treatment fastness, of the dye composition are excellent, and the dye composition can be widely used in coloring of cellulose fibers, polyamide fibers, protein fibers, blended textiles and the like. The dye composition has an unexpected coloring effect during union dyeing of brocade/cotton and brocade/viscose blended fabrics and interlacing fabrics by means of the one-bath and two-step method. Please see the formulas in the description.