Use polyethylene glycol (PEG), Ymer N120, poly propylene glycol (PPG) and isophorone diisocyanate (IPDI) to synthesize polyurethane (PU) prepolymer with triethanolamine. Triethanolamine was used as a cross-linking agent. Then the prepolymer was immersed in the mixed solution of bletilla striata polysaccharide (BSP) and acrylamide (AM) to prepare BSP-loaded PU/PAM double network hydrogel through free radical polymerization. The structural characteristics, mechanical properties and biological properties of the hydrogel were characterized by FTIR, SEM, tensile compression and biological tests. The results showed that when the amount of triethanolamine added is 60% (the mole fraction of polyol), the dual network hydrogel had a high swelling rate (203%) while maintaining a certain tensile strength (1.9 MPa) and high compressive strength (22.7 MPa). The double-network hydrogel had antibacterial and antioxidant effects. The antibacterial bandwidths of Escherichia coli were 0.5 mm~4 mm. And the antibacterial bandwidths of Staphylococcus aureus were 0.5 mm~3.5 mm. The scavenging rate of hydroxyl radical was up to 28%. The rate of hemolysis was less than 5 %. And the rate of cell survival was up to 101.3%. Those can indicate that the double network hydrogel had good biocompatibility.