The invention relates to printing and dyeing ink for a direct inkjet textile and a preparation method thereof, the printing and dyeing ink comprises reactive dye, N-methyl-2-pyrrolidone, ethylene glycol monomethyl ether, isopropanol, propanetriol, triethanolamine and deionized water, the printing and dyeing ink for the direct inkjet textile comprises red printing and dyeing ink / yellow printing and dyeing ink / blue printing and dyeing ink / black printing and dyeing ink, and the preparation method of the printing and dyeing ink for the direct inkjet textile is as follows: weighing the reactive dye, the N-methyl-2-pyrrolidone, the ethylene glycol monomethyl ether, the isopropanol, the propanetriol, the triethanolamine and the deionized water respectively, placing in a stirring container, stirring uniformly, then standing, and filtering so as to get a finished product, namely the printing and dyeing ink for the direct inkjet textile. The printing and dyeing ink is excellent in quality, low in price, applicable to different models of inkjet printing machines, abundant and bright in color, strong in stability, strong in coloring power and small in undissolved substances, and can be used for automatically cleaning a spray head, ensuring no blockage and achieving good flowability and smooth jet; and furthermore, wrinkling and diffusion of an image of the direct inkjet textile can be avoided, the color fastness is high, the resistance to ultraviolet radiation is realized, the image can be preserved for 20 years without color fading, and the inkjet printing machine in a shutdown statecan not block the head within half a year.