Objective To investigate the effects of combined treatment with theaflavins and modified atmosphere packaging (MAP) on the quality of air-dried hairtail (Trichiurus lepturus) during refrigerated storage.Methods Several indices of air-dried hairtail are measured during refrigerated storage, including peroxide value (PV), thiobarbituric acid reactive substances (TBARS), DPPH radical scavenging activity, hydroxyl radical scavenging activity, superoxide anion radical scavenging activity, and total bacterial count (TBC).Results The combination of 70% CO₂+30% N₂ MAP and 0.3 g/kg theaflavins significantly inhibits the increase in PV and TBARS values (P<0.05), enhances the free radical scavenging capacity (P<0.05), and results in higher sensory evaluation scores. Moreover, the TBC of air-dried hairtail treated with 70% CO₂+30% N₂ MAP and 0.3 g/kg theaflavins is found to be significantly lower than that of other groups (P<0.05). After 10 days of refrigerated storage, the TBC is 5.40 log(CFU/g), which is 46.27% lower than that of the control group. Correlation analysis indicates a close relationship between the degree of lipid oxidation, spoilage, and antioxidant capacity.Conclusion The quality of air-dried hairtail during storage is effectively maintained by the combined treatment of 70% CO₂+30% N₂ MAP and 0.3 g/kg theaflavins.