An edible polysaccharide film with high tensile strength and biodegradability was prepared by freeze–thaw treatment with sodium alginate (SA) and hyaluronic acid (HA) and cross-linking with calcium lactate. The SA/HA ratio, the calcium concentration, the number of freeze–thaw cycles, and the calcification time all have significant effects on the tensile strength of SA/HA films. An increase in tensile strength was obtained due to the reaction of 3% calcium lactate with 60% SA. Compared with the control group, the tensile strength of the SA/HA films developed in this study increased by 214% from 3.188 to 10.02 MPa. The compatibility of films was evaluated by Fourier transform infrared spectroscopy; the absorption peaks of SA and sodium hyaluronate had shifted to a wavelength of 3,403 ~ 3,411 cm−1 after freeze–thaw treatment, and a strong interaction occurred at a wavelength of 1,328 cm−1. In addition, the swelling and solubility of the SA/HA film decreased by half during the freeze–thaw period. Further, scanning electron microscopy showed that the cross sections of the films were uniform and compact after two freeze–thaw treatments. SA/HA films that exhibited increased tensile strength and that had the potential to overcome the poor water vapor barrier problems traditionally experienced with these films were developed in this study.