The oregano essential oil (OEO) nanoemulsion was prepared, and the effects of different added amounts of OEO nanoemulsion on the mechanical and antibacterial properties of PSE-like chicken protein isolate (PPI) film were investigated. Results revealed that the nanoemulsion containing 12 % Tween 80 and 6 % OEO had the smallest particle size (82.46 nm) and the best stability. Compared to the control group, the film of the PPI/OEO-2.5 % treatment group demonstrated superior mechanical properties. With the increase of the concentration of OEO nanoemulsion, the UV transmittance and water contact angle of the films decreased gradually (more hydrophilic), the opacity and water vapor permeability significantly increased, while the thermal stability, antioxidant properties (DPPH scavenging activity, 17.07 % ∼ 56.00 %), and antibacterial properties were markedly enhanced. The PPI/OEO-2.5 % treated film was applied to the preservation of pork, extending the shelf life by 2-4 days. These findings suggested that PPI had great application potential in bioactive packaging materials.