The invention belongs to the fine chemicals synthesis technical field, and discloses a method for synthesizing a copolymer polycarboxylate series non-formaldehyde crease-resistant finishing agent. The method adopts a clean aqueous solution polymerization technology, and comprises the following steps of: selecting H2O2-maleic anhydride as an initiator to perform a polymerization reaction at a reflux temperature with continuously dropping acrylic acid or an aqueous solution of the acrylic acid and vinyl acetate; synthesizing bipolymers and multi-element copolymers, which are terminated by carboxyl and use maleic anhydride and the acrylic acid as main monomers, through adjusting the proportions of the monomers and the dosage of the initiator. When the non-formaldehyde crease-resistant finishing agent is used as a non-formaldehyde crease-resistant finishing agent for textiles, thereby the crease recovery capability of the textiles can be improved.