Abstract: To address postharvest fungal decay in blueberries, this study developed chitosan-based nanoemulsions containing oregano essential oils (OEO) and thyme essential oils (TEO) in varying concentrations via high-speed homogenization. The structure and properties of the nanoemulsion and the preservation pad were characterized by particle size, polydispersity index, embedding rate, loss rate and scanning electron microscopy (SEM). Combined with antibacterial activity tests and room temperature storage experiments, the inhibitory effects of preservation pads on Botrytis cinerea (postharvest pathogen in blueberries) and their impact on storage quality were comprehensively evaluated. The results demonstrated high uniformity, effective encapsulation, and stable distribution of essential oil nanoparticles across the pad surface. Antimicrobial activity assays showed a positive correlation between essential oil concentration and pathogen inhibition efficacy. Under ambient storage conditions, the preservative pad containing 45 μL/L OEO exhibited the most effective suppression of blueberry decay. After 8 days of storage, the control group showed evident softening and spoilage, whereas blueberries treated with CS-OP3 (45 μL/L OEO) and CS-TP2 (85 μL/L TEO) maintained favorable flavor and color, with less than 3% loss in soluble solids, significantly reduced weight loss and disease index, and a slower decline in titratable acidity (P<0.05). This treatment effectively extended the shelf life of 'Canlan' blueberries from 4~6 days to over 8 days compared to untreated fruit, while maintaining their commercial value. These findings highlight a promising, cost-effective, and natural strategy for extending the postharvest shelf life of fruits and vegetables, with potential applications in commercial blueberry preservation.