The invention relates to a preparation method of black matt polyimide film, including preparation of polyamic acid solution, preparation of black pulp, preparation of black matt resin solution and steps of curtain coating, drying and dehydration cyclization. The matting agent is any one of a silicon dioxide, an aluminum oxide, a zirconium oxide and a ferric oxide. Addition method has two modes, one includes that the matting agent and the black pulp are added into the prepared polyamic acid solution to be fully mixed for curtain coating, drying and dehydration cyclization so as to prepare the black matt polyimide film; the other one includes that the matting agent and the black pulp are evenly mixed with reagent of an aromatic diamine in proportion and then react with an aromatic dianhydride so as to directly prepare the black matt polyamic acid resin solution, and then curtain coating, drying and dehydration cyclization are carried out to prepare the black matt polyimide film; the filmhas the properties that elongation is more than or equal to 40%, tensile strength is more than or equal to 150MPa, dielectric strength is more than or equal to 80KV/mm, visible light transmission isless than or equal to 1%, absorbency is 0.92%, and luster in air at 60 DEG C is 59.