Abstract: Quinoa saponins and silver nitrateas raw materials, the complexes of quinoa saponins with nano-silver were prepared by biological reduction method, and the antibacterial activity of the complexes was studied. The complexes of quinoa saponins and silver nanoparticles were characterized and analyzed by ultraviolet-visible spectrophotometer(UV-vis spectrophotometer) and transmission electron microscope(TEM). The synergistic antibacterial activity of quinoa saponins and silver nanoparticles were studied by bacteriostatic circle experiment, minimal inhibitory concentration(MIC) experiment, minimum bactericidal concentration(MBC) experiment and so on. The results showed that the complex of quinoa saponins with silver nanoparticles was spherical, and the diameter of the particles was mostly concentrated around 10 nm, with good dispersity. Characteristic absorption peaks appear at 420 nm. The complex of quinoa saponins and nano-silver preform had good inhibitory effect and synergistic inhibitory effect on foodborne microorganisms, and had good inhibitory effect on Staphylococcus epidermidis and Staphylococcus aureus, the bacteriostatic diameter were(11.33±0.58) and(10.67±1.15) mm, respectively. The low toxicity to normal gastric mucosal epithelial cell(GES) and gastric cancer cell(SGC). As a biological reducing agent, quinoa saponins enhanced the solubility and dispersion of silver nanoparticles, retained the broad-spectrum antibacterial properties of silver nanoparticles, and cooperated with each other to enhance their antibacterial properties.