The invention relates to a preparation method of a cross-linking agent for pigment printing. The preparation method comprises the following steps: under the effect of a catalyst, controlling the reaction temperature to be 60-120 DEG C, and reacting acid with alcohol to generate esters; controlling the reaction temperature to be 40-60 DEG C and dissolving the esters by using a solvent; and controlling the temperature to be 40 DEG C or below, adding an accelerant, a preservative, a defoamer and a thickener, and stirring uniformly to prepare the cross-linking agent for pigment printing. Compared with the prior art, the preparation method of the cross-linking agent for pigment printing has the advantage that the PH value of the product is neutral at the normal temperature. After the cross-linking agent is added in printing paste, along with increasing of the temperature in a baking process of fabrics, the esters are hydrolyzed to generate the acid and the alcohol, the acid and the alcohol not only can promote cross-linking of polyacrylate emulsion, but also can participate in cross-linking reaction; the printing durability is improved; and the esters which are not hydrolyzed and the solvent can improve hand feeling of the fabrics.