This study explored the preservative effect and shelf-life extension of chilled mutton by coating with a mustard essential oil-based Pickering emulsion. It also provided data to support the practical application of such emulsions in meat preservation. The experiment involved applying a mustard essential oil Pickering emulsion as a surface coating on chilled mutton, and the study assessed the emulsion's antioxidant activity, antibacterial performance, and impact on mutton quality indicators. Results indicated that increasing the concentration of mustard essential oil significantly enhanced the emulsion's antibacterial effect (P<0.05), with varying inhibitory effects on different bacteria at the same concentration. At a 2.0% v/v concentration, the Pickering emulsion exhibited good antioxidant and antibacterial properties. The inhibition zones for four pathogenic bacteria measured 20.20±0.11, 19.07±0.06, 12.13±0.06, and 10.73±0.06 mm, respectively. The DPPH, ABTS⁺, and OH radical scavenging activities were 89.45%, 66.61%, and 94.5%, respectively. Regarding preservation, indicators such as pH, meat color, TVB-N content, TBARs value, carbonyl and thiol content, total bacterial count, and coliform count in the soaking and spraying groups were significantly better than those in the control group (P<0.05). Notably, the pH in both groups remained within the fresh meat range on the 28th day of storage. The TBARs value remained within the acceptable range within 21 days, and the carbonyl content during storage was significantly lower than that in the control group (P<0.05). The control group samples began to deteriorate by the 7th day, while the soaking and spraying groups extended the storage period to 14 and 21 days, respectively. In conclusion, the mustard essential oil Pickering emulsion effectively improves the preservation of chilled mutton and extends its shelf life, with the 2.0% v/v concentration offering optimal antioxidant and antibacterial performance. The soaking treatment outperformed the spraying method, showing potential for broader application in meat product preservation.