The invention belongs to the field of dye mixtures and in particular relates to a black dye composition and an application thereof in polyamide microfiber leather dyeing. The black dye composition comprises the following components in parts by weight: 50-90 parts of a component A and 5-30 parts of a component B, wherein the component A refers to a compound shown as a formula (I) or a formula (II) in the specification; and the component B refers to a compound shown as a formula (III) in the specification. The black dye composition disclosed by the invention has high blackness, excellent color fastness and high dye permeability and is very suitable for polyamide microfiber leather dyeing.