The invention relates to a method for preparing a hydrogel with optical activity, which pertains to the field of polymer material. The method comprises the following steps: firstly, an N-propargyl amide monomer with double bond is synthesized, the monomer is then copolymerized with N-propargyl amide, N-propargyl carbamide or N-propargyl sulfonamide monomer with chiral substituent to synthesize a copolymer with stable helical structure and rather high optical activity; then the copolymer obtained is dissolved in a chloroform solvent, propyl acrylamide (NIPAm) and N, N`- methylene bisacrylamide(Bis) are dissolved in chloroform, the NIPAm dissolved is added into the copolymer solution and heated up to 45 DEG C to 90 DEG C under the protection of nitrogen; an evocating agent AIBN is added under the protection of nitrogen, reaction lasts for 30min to 24h and then a yellow clear gel is obtained. The gel is put into the chloroform solvent to be soaked and cleaned for a plurality of times, dried, soaked and swollen by deionized water and then the hydrogel is obtained. The prepared hydrogel has optical activity.