The invention discloses a non-iron crease-resistant finishing agent of formaldehyde-free cellulose fabrics and a preparation method thereof, aiming at the problem that the prior non-iron crease-resistant finishing agent has high requirements for the raw materials used for synthesis or has no ideal non-iron effect and firmness on the fabrics. The non-iron crease-resistant finishing agent is composed of unsaturated acid monomer and acrylate that are polymerized in aqueous phase under the actions of initiator, regulator and catalyst, the regulator is convenient for performing penetration and esterification cross-link reaction, and has good cross-link effect, the catalyst has good catalyzing effect and complete reaction. The non-iron crease-resistant finishing agent has the advantages of outstanding non-ironing crease-resistance performance, less yellowing and higher strength reservation.