Abstract: In this study, hydroxyapatite (HAp) derived from mussel shells was used as stabilizer to prepare HAp-Pickering emulsion (HAp-PE). The effects of different oil-to-water ratios and HAp mass fractions on the stability and rheological properties of HAp-PE were analyzed. Based on the experimental results, the optimal conditions were established for the preparation of HAp-PE loaded with fucoxanthin (Fx) to form HAp-PE-Fx. Subsequently, the influence of varying Fx concentrations on the antioxidant and antibacterial properties of HAp-PE-Fx was evaluated. The optimal Fx concentration was then used to prepare HAp-PE-Fx for the preservation of tuna fillets. Results indicated that an oil-to-water ratio of 60:40 and a HAp mass fraction of 6% yielded HAp-PE with the smallest droplet size (49.71 µm), the highest emulsification index, and the greatest apparent viscosity, signifying optimal stability. At a Fx concentration of 0.75 mg/mL, HAp-PE-Fx demonstrated excellent antioxidant activity and antibacterial activity against Escherichia coli and Staphylococcus aureus. Furthermore, HAp-PE-Fx effectively preserved meat color as well as reduced pH, total volatile basic nitrogen content and thiobarbituric acid reactive substance value, inhibited microbial growth in tuna fillets during storage. These findings suggest that HAp-PE-Fx effectively retards tuna spoilage at 4 ℃, presenting an advantageous preservation effect.