Method for improving dyeing uniformity and fastness of anionic pigment

Belonging to the technical field of textile printing and dyeing, the invention relates to a method for improving the dyeing uniformity and fastness of an anionic pigment. The method includes: firstly using low viscosity chitosan and cooperatively using citric acid and sodium hypophosphite for pretreatment to realize even dyeing of a pure cotton fabric by an anionic pigment, then employing high viscosity chitosan and butanetetracarboxylic acid, sodium hypophosphite, glycerin and polyethylene glycol to perform aftertreatment on the dyed cotton fabric, thus generating a synergistic effect and significantly improving the pigment coloring fastness.