1. The cationic groups such as quaternary ammonium salt or tertiary amine salt in the color fixing agent are used to bond with ionic groups in the ionic structure of the dye, so that the dye and the fixing agent form an insoluble color block to settle on the fiber, so as to improve the color fastness of the dye on the fabric.

2. The dye water solubility is reduced by cross-linking reactive groups in the dye molecules with reactive groups on the dye molecules and hydroxyl groups on the cellulose molecules.

3. Use the film forming performance of fixing agent on the fabric to improve its dyeing fastness.In the high-temperature drying process of the fabric treated with color fixing agent, the reaction groups on the color fixing agent molecules crosslink themselves into macromolecules, forming a protective film with certain strength on the surface of the fabric and fiber, and covering the dye on the fiber, making it difficult for the dye to fall off.