The effects of the dosage and grinding time of the super dispersant polyethylene oxide-thick cyclic aromatic hydrocarbon block copolymer on the particle size, thermal stability and centrifugal stability of pigment violet 23 were studied. The microscopic dispersion of ink was observed by TEM, and the mechanism of dispersant on pigment violet was analyzed by infrared spectroscopy. The results showed that the particle size of the purple paste was up to 138nm, and the dispersion stability was the best, after grinding for 2.5h with 15% super-dispersant. The adsorption between the dispersant and the pigment violet is driven by the adsorption of the hydrophobic group of the dispersant -- the thick cyclic aromatic hydrocarbon and the benzene ring structure of the pigment violet 23 by accumulation, which causes the infrared absorption change of the C-H bond. The thixotropic value is 5.47, which is in line with the national standard. And the long-term storage of ink, line, hydrolytic resistance are better.