In order to investigate the antioxidation and antibacterial effect of polyphenols from Lyophyllum Cinoraseens Konr & Maubl, crude polyphenols after ultrasonic-assisted ethanol extraction purified polyphenols with macroporous resin were used as raw materials to study the scavenging effect for ·OH, O · and DPPH· and antibacterial effect by the filter paper disc method. The results showed that crude polyphenols and purified polyphenols from Lyophyllum Cinoraseens Konr & Maubl both exhibit the scavenging effect for ·OH, O · and DPPH·, and there presented certain dose-effect relationship between scavenging ability and the concentration of polyphenols. Crude polyphenols and purified polyphenols showed different antibacterial activity against five tested microorganisms(Escherichia coli, Salmonella typhi, Staphylococcus aureus, Bacillus subtilis, Saccharomyces cerevisiae), and both of them had the strongest antibacterial effect on Saccharomyces cerevisiae under the same concentration. Purified polyphenols had the weakest antibacterial effect on Escherichia coli, while crude polyphenols had no antibacterial effect on Escherichia coli. The inhibitory effect on five tested microorganisms was positively correlated with the mass concentration of purified polyphenols. In addition to Escherichia coli, the inhibitory effect of on other four tested microorganisms was also positively correlated with the concentration of crude polyphenols. The antibacterial activity of purified polyphenols was better than that of crude polyphenols at the same concentration.