The invention discloses a formaldehyde-free fixing agent, which comprises the following components in parts by weight: 80 to 120 parts of cationic monomer, 5 to 20 parts of unsaturated high-grade organic amine monomer, 3 to 10 parts of dicyandiamide, 4 to 18 parts of pH regulator, 0.001 to 0.05 part of metal ion chelating agent, 0.5 to 1 part of initiator, 2 to 10 parts of epichlorohydrin and 20 to 50 parts of deionized water. The formaldehyde-free fixing agent provided by the invention does not contain formaldehyde and alkylphenol ethoxylates (APEO); and meanwhile, the film-forming property of the fixing agent is utilized, a meshed film layer can be formed on the surface of the fiber, so that the dye dissolution is reduced, the color fastness of reactive dye dyed fabrics is improved, a fixing effect is good, the formaldehyde-free fixing agent can be applied to fixing colors of the reactive dye dyed fabrics, and the washable color fastness and boiling water soaking fastness of the fabrics are improved.