In this study, a novel chlorine dioxide (ClO2) microcapsule with a performance of moisture-triggered release was fabricated followed by the mixing with polylactic acid (PLA) for the preparation of an antibacterial packaging film. ClO2 microcapsules were first prepared by encapsulating stable ClO2 solution (NaClO2 as the main component) in a PLA shell, and the resulting microcapsules together with tartaric acid were applied as antibacterial components for antimicrobial PLA film using solvent casting method. The impact of ClO2 microcapsules on the antimicrobial effectiveness, oxygen and water vapor barrier properties, mechanical behavior, and thermal stability of PLA films was investigated. The results showed that the addition of ClO2 microcapsules at a concentration of 20% imparted PLA films excellent antimicrobial properties with a growth inhibition of Escherichia coli and Staphylococcus aureus by 4.95 log CFU/mL and the antibacterial rate was 99%. Furthermore, the tensile strength of the films with ClO2 microcapsules at a concentration of 20% was 21.20 MPa, which was 19% higher than that of the PLA film without microcapsules. The oxygen and water vapor transmission rates reached 2800 cm(3) m(-2) 24 h(-1) and 20.00 g m(-2) 24 h(-1), respectively, and the barrier properties were improved by 20 and 36.14%. Thermogravimetric analysis showed that the generated film was stable before 193 A degrees C. Scanning electron microscopy analysis confirmed a good compatibility between the ClO2 microcapsules and the PLA matrix, and the emerged voids indicated the generation of ClO2 and its release from the antimicrobial film. An obvious sustained release of ClO2 from the antimicrobial film completed until 240 h. The release behavior fitted the logistic model, and the release mechanism followed the S model. This study may provide a feasible approach for the development of food packaging materials with efficient antibacterial activity and sustained-release performance.