Abstract: In this study, the anti-solvent co-precipitation method was used to prepare a composite system consisting of zein and hyaluronic acid (HA) loaded with ellagic acid (EA), resulting in a highly stable nanoparticle delivery system. The encapsulation effect was verified using fluorescence spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction and field emission scanning electron microscopy. Structural changes were analyzed, and the stability, antioxidant activity and in vitro release characteristics of the composite nanoparticles were evaluated. The results showed that when the EA addition amount was 15 mg, the particle size of the ellagic acid-zein-hyaluronic acid (15 EA-Zein-HA) composite nanoparticles was 798.2±3.99 nm, the encapsulation efficiency was 88.46%±0.12%, and the loading capacity was 6.73%±0.021%. The composite nanoparticles were combined through electrostatic attraction, hydrogen bonds and hydrophobic effects. The secondary structure of zein was changed after the combination with hyaluronic acid and ellagic acid. The 15 EA-Zein-HA composite nanoparticles had good stability, and compared with that of free EA, the retention rate of EA in the composite nanoparticles was increased by 1.31, 1.39 and 1.54 times after 120 min ultraviolet irradiation treatment, 10 min heat treatment at 85 ℃ and 20 ℃ storage treatment for 20 days, respectively. Encapsulating EA into 15 EA-Zein-HA nanoparticles significantly enhanced its antioxidant activity and the sustained release effect of EA (P<0.05). The research findings can be used for the development of an innovative delivery system for functional components.