The research in biopolymer-based superabsorbents is gaining importance in the green chemistry field thanks to their environmentally friendly properties. In this study, a biopolymer-based superabsorbent made of calcium ion crosslinked alginate/carboxymethyl cellulose composite was prepared by a new quasi-cryogelation process, where the complete ionic gelation takes place before the freezing step, in contrast to the conventional cryogelation technique in which gelation occurs under semi-frozen conditions. Thanks to the facile quasi-cryogelation method, the morphology of the gels changed and a significant increase in water absorption properties has been achieved. The swelling properties of the material were investigated in distilled water and different physiological fluids. Results show that the proposed material shows good water absorption property where a water absorption of 2343% was reached and even after five cycles this value was 1200%. As a result, this study reports a biopolymer-based sustainable superabsorbent which is appropriate for various applications such as the removal of pollutants from water or diaper production.