Abstract: The present invention relates to a dye-salt separation membrane and a preparation method thereof. The method includes the following steps: firstly pouring an aqueous phase solution containing tannic acid and anhydrous piperazine on a surface of a polysulfone-based ultrafiltration base membrane at a mass ratio of the tannic acid to the anhydrous piperazine of 1:2 to 2:1, followed by complete infiltration, and draining the aqueous phase solution; and then pouring an organic phase solution of trimesoyl chloride on the surface of the base membrane, and draining the organic phase solution to obtain the dye-salt separation membrane. The method of the present invention is simple and easy to implement, and the dye-salt separation membrane prepared by the method has a relatively high solution permeability, an efficient dye retention and permeability of inorganic salts, thereby achieving an excellent dye-salt separation effect.