The invention discloses a method for preparing a matt black
polyimide film. The method comprises I, preparing a
polyamic acid resin solution through a conventional method, II, preparing black
slurry of which the use amount is 2-20 wt% the
solid content M of the
polyamic acid resin solution, III, preparing a matting agent dispersion liquid of which the use amount is 2-20wt% M, IV, preparing a black
polyamic acid resin solution through blending the polyamic acid resin solution, the black
slurry and the matting agent dispersion liquid through stirring, and carrying out defoaming for next use, and V, carrying out
curtain coating, drawing, imidization and setting on the black polyamic acid resin solution through conventional processes, wherein after biaxial drawing, imidization or setting, thefilm is subjected to surface treatment at a high temperature of 640-800 DEG C for 5-120s so that the matt black
polyimide film is obtained. The black
pigment and the matting agent have moderate average particle sizes. In the resin solution
curtain coating, the high temperature surface treatment is used. The film has improved light
transmittance, gloss and physical and mechanical properties.