Objective To study the preservation effect of ozone on fresh peanuts.Methods "Four Red" fresh peanuts were used as experimental materials. Peanuts were treated with ozone at different concentrations (10, 30, and 50 mg/L) and stored at (4 ± 1) ℃ for 15 days. Edible quality, nutritional quality, and safety quality were measured every 3 days.Results The effects of ozone treatment on the post-harvest storage quality of fresh peanuts varied with concentration. Compared with the control group, medium-to-low concentration ozone treatment (≤30 mg/L) effectively reduced peanut mass loss, inhibited mold development and microbial growth, maintained stable kernel color and good texture, and delayed lipid and oil oxidation in cell membranes, thereby preserving nutritional quality. In contrast, high-concentration ozone treatment (50 mg/L) accelerated quality deterioration during storage, particularly in the later stages, manifesting as intensified color changes, faster nutrient degradation, and accelerated lipid and oil oxidation. The optimal preservation effect was observed at 30 mg/L ozone.Conclusion Ozone treatment is a suitable preservation technique for delaying post-harvest quality deterioration and extending the shelf life of fresh peanuts.