As a natural polymer material with abundant sources, cellulose has good biocompatibility and degradability, but its application was limited due to its difficulty in dissolution. In this paper, the ionic liquid 1-allyl-3-methylimidazole chloride (AmimCl) was used to dissolve cellulose (Cel). The mixed aqueous solution of sodium alginate (SA) and gelatin (Gel) was used as coagulation bath to regenerate cellulose. Then, a transparent, high- strength composite hydrogel was prepared by soaking in calcium chloride solution for crosslinking sodium alginate. The effects of cellulose concentration (3%, 4%, 5%, 6%, 7% and 8%) and different sodium alginate/gelatin mass ratios (0:10, 2:8, 4:6, 6:4, 8:2 and 10:0) on the performance of hydrogels were investigated respectively. The physical properties of the hydrogels were characterized by FT- IR, SEM, XRD, UV- Vis and universal material testing machine. The results show that the hydrogen bonding between the components in hydrogel and the ion interaction between sodium alginate and Ca²⁺ endow the hydrogels with excellent mechanical properties. Compared with the regenerated cellulose hydrogel prepared with pure water as coagulation bath, the strength is increased by 26.36%. With the increase of cellulose concentration, the crystallinity of the hydrogels and density of the network structure increase, and the mechanical properties of the hydrogels are significantly improved. In addition, the ratio of sodium alginate to gelatin also has a significant impact on the performance of the hydrogels. When the mass ratio of sodium alginate to gelatin is 6:4, the mechanical performance of the hydrogel is best, which can reach 2.349 MPa. The degradability test shows that the hydrogel has good biodegradability, which has a wide range of potential applications.