Bacterial cellulose (BC), produced by bacteria and fungi, is a promising material in the biomedical field. However, non-antibacterial activity limits its broad applications. Herein, antibacterial composites (BC/ZIF-8-iodine) were prepared by loading iodine into zeolitic imidazolate framework-8 (ZIF-8) modified BC (BC/ZIF-8). BC/ZIF-8-iodine was well characterized by SEM, XRD, FTIR, XPS, Raman and contact angle analyses. The increase of ZIF-8 content augmented the loading capacity of iodine in BC/ZIF-8-iodine. Meanwhile, the adsorbed iodine can be released from BC/ZIF-8-iodine composites, following the Higuchi equation. A reduced sublimation of iodine was observed in BC/ZIF-8-iodine composites, indicating their good iodine preservation ability. BC/ZIF-8-iodine composites exhibited strong antibacterial activity towards Escherichia coli, Staphylococcus aureus and Candida albicans. XPS and Raman analyses indicated that the adsorbed iodine of BC/ZIF-8-iodine composites was in the form of I3-. The expected iodine loading, release and preservation behaviors of BC/ZIF-8-iodine composites ensure their antibacterial performance and suggest potential clinical applications.