With polyvinyl alcohol (PVA) as the main raw material, flavonoids were extracted from green tea and were used as antibacterial agents to prepare green tea flavonoid extract/PVA film with good antibacterial properties. The method uses composite enzymatic hydrolysis to extract total flavonoids from green tea, and determines the antioxidant activity and antibacterial ability of total flavonoids in green tea. Mix the green tea extract with PVA in proportion, and use the casting coating method to form a composite preservation film. The results show that the volume ratio of green tea extract to PVA is 4∶6, which is the most suitable and has good mechanical and optical properties. The reducing power of total flavonoids in green tea is positively correlated with absorbance. DPPH radical scavenging ranged from 85% to 90% and OH radical scavenging ranged from 25% to 50%. Green tea extract has significant antibacterial effects on Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes. Green tea/PVA composite film has a more significant inhibitory effect on Staphylococcus aureus with an inhibitory circle diameter of 8.60 mm. The study provides new ideas for new food packaging materials and realizes the comprehensive utilization of green tea.