In order to prolong the shelf life of food safely and effectively, this study utilized the properties of zein and sodium caseinate to prepare composite nanoparticles loaded with carvacrol by pH-driven method. The zein/sodium caseinate composite nanoparticles had a good encapsulation efficiency (77.96% ~ 82.19%) for carvacrol. Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) analysis showed that carvacrol was loaded successfully. Scanning electron microscopy (SEM) showed that the composite nanoparticles were spherical, with a particle size range of 70 ~ 200 nm, and had strong antioxidation activity and antibacterial activity. When the composite nanoparticles were used in food packaging, they could effectively inhibit food spoilage and prolong the shelf life of food, which has potential application prospect in the food industry.