Waterborne polyurethane(WPU) was prepared by using 2,4-dihydroxybenzaldehyde (DDBA) as the chain extender and hydroxyethyl acrylate (HEA) as the blocking agent. The polyurethane-CMCh Schiffbase was synthesized by the carboxymethylated chitosan (CMCh) under mild conditions. Then the polyurethane-carboxymethyl chitosan Schiff base (DPU-Ch) hydrogel was synthesized by free radical polymerization. The structure and properties of hydrogels were characterized by FTIR, SEM, mechanical properties, swelling water retention test, antibacterial test and blood compatibility test. The results show that the mechanical properties of the hydrogel increase with the increase of the CMCh mass fraction. At the same time, the hydrogel also shows good swelling ability and proper water retention capacity. When the amount of CMCh added is 2%, the hydrogel shows good antibacterial properties against E. coli and S.aureus; The hemolysis rate of the hydrogel is lower than 5%, indicating that it has good cell compatibility, and the survival rate of NIH3T3 cells above 90% proves that it is not cytotoxic, so It has potential application prospects in the field of biomedicine.