In this work, a micro/nanofiber antibacterial pad with a core–shell structure was successfully designed to extend the shelf life of the cold fresh lambs. The micro/nanofiber was prepared by electrostatic spinning using polylactic acid as the shell and Eudragit L 100–55 as the core, and 0.4% (w/w) tea polyphenols (TP) as an antibacterial agent was encapsulated in the core section. Release behavior showed that TP could be effectively protected in an acidic environment to achieve a slow‐release effect. The antibacterial experiment revealed that the antibacterial rates of the coaxial antibacterial pad containing 0.4% TP against Escherichia coli and Staphylococcus aureus were 73% and 53.88%, respectively. As a result, freshness preservation experiments, using an antibacterial pad with the core–shell structure, could extend the shelf life of the cold fresh lamb. Novelty impact statement The micro/nanofiber antibacterial pad with a core–shell structure was prepared. The antibacterial pad with a core–shell structure could control the slow release of tea polyphenols. The micro/nanofiber antibacterial pad could extend the shelf life of the cold fresh lamb.