Abstract:This experiment was conducted to investigate the application value of chamomile residues by analyzing the composition and antibacterial activity of chamomile residues.Through the identification and content determination of phenolic acid，polysaccharides，and flavonoids in each polar site，this paper preliminarily determined the effective antibacterial substances.The antibacterial activity of each polar part against Staphylococcus aureus，Escherichia coli，Bacillus subtilis，and Pseudomonas aeruginosa was determined by using the perforation method and tube double dilution method.The effects of ethyl acetate extract from chamomile residue on the growth curve，electrical conductivity，cell wall integrity，extracellular polysaccharides，and extracellular protein of S.aureus were explored.The results showed that all the polar parts of chamomile residue contained flavonoids，among which the ethyl acetate extract contained the highest amount of flavonoids（31.53mg/g）.Theethyl acetate extract had the strongest antibacterial effect on S.aureus with the minimum inhibitory concentration（MIC）of 15.63 mg/mL.The diameter of the inhibition circle was（19.73±0.45）mm.The antibacterial mechanism test showed that after the treatment of S.aureus with ethyl acetate extract，the content of the cells flowed out，the extracellular protein and polysaccharide content increased significantly，and the conductivity of the culture solution of the bacteria also increased significantly.