Abstract: The application of myofibrillar protein in food processing is limited due to its shortcomings, such as its proneness to oxidation and poor stability. Therefore, the rigorous storage conditions are always required. In the current study, a hydroxy radical oxidation system was constructed and the effects of different addition levels of citrus extract (hesperidin, 0%, 1.5%, 3.0%, 4.5%, and 6.0%) on pork myofibrillar protein were analyzed in terms of protein color, particle size, zeta potential, dimer tyrosine content, surface hydrophobicity, and other oxidative indices. These effects were studied from the perspectives of UV spectroscopy and intrinsic fluorescence intensity to analyze how hesperidin addition levels influence the structure and functionality of pork myofibrillar protein. The results indicate the addition of hesperidin significantly improve the color stability of the pork myofibrillar protein under oxidative stress. The absolute value of its zeta potential reaches 7.75 mV (6.0%), and there is no significant difference from that of unoxidized protein. The surface hydrophobicity index also increases from 2.1 to 6.6 μg, indicating an enhancement in the stability of the pork myofibrillar protein system. The particle size decreases from 846 nm to 583 nm, and the dimer tyrosine content reduces from 245 AU to 211 AU, indicating a slowing down of the protein system’s oxidation rate. The addition of hesperidin reduce the degree of denaturation of the aromatic structure of amino acid residues in pork myofibrin under oxidative stress. This study can provide a theoretical foundation for applying hesperidin in meat products.