The invention provides a preparation method of a black polyimide thin film with a matte surface. The preparation method comprises the following main steps: I, preparing a polyamic acid resin solutionaccording to a conventional method; II, preparing black slurry, wherein the amount of a black pigment is 2 to 20 weight percent of solid content M in the polyamic acid resin solution; III, preparing ablack polyamic acid resin solution; blending and stirring the polyamic acid resin solution, the black slurry and an agglomeration agent, and de-foaming for later use; IV, after enabling the black polyamic acid solution to pass through a filtering system, treating a conveying pipeline through a magnetic field or ultrasonic waves; finishing magnetic field and ultrasonic agglomeration treatment on the resin solution; then conventionally preparing the black polyimide thin film with the matte surface. According to the preparation method provided by the invention, the average grain diameter of theblack pigment is 0.01 to 0.8mu m; the agglomeration agent is added in a polyamic acid resin condensation polymerization synthesis process; the light transmittance, the glossiness and the physical andmechanical properties of the thin film are remarkably improved.