The invention discloses a black-series polyimide nano-fiber filament yarn and a batch preparation method thereof, belongs to the technical field of chemical fiber dyeing, and solves a problem existingin a preparation process of current black polyimide fibers that carbon black particles or carbon nano tubes are difficult to be dispersed in polyamide acid stock solution so that electrostatic spinning is difficult to be continuously performed. The black-series polyimide nano-fiber filament yarn is prepared by the following steps: through adding an easily-carbonized soluble polymer to the polyamide acid spinning stock solution, to obtain homogeneous polyamide acid spinning solution; and through an electrostatic spinning technology, imidization treatment, low-temperature carbonization, hot-drawing, and twisting, to obtain the black-series polyimide nano-fiber filament yarn, wherein breaking strength thereof is greater than 3.0 cN/dtex, a washable fastness is 5 levels, and a light fastnessis 6 levels. The black-series polyimide nano-fiber filament yarn has the characteristics of uniform color, high color fastness, no color difference, uniform thickness, excellent mechanical property and the like.