In order to study the effect of epigallocatechin on the oxidation of myosin in sea bass under microwave heating，differentmass concentrations of epigallocatechin (20，40 μg/mL and 60 μg/mL) were used to inhibit myosin oxidation and study the mechanism of its effect on myosin. EGC could delay the increase of carbonyl content and dityrosine of myosin and the decrease of total sulfhydryl content after microwave treatment. Carbonyl content was reduced by 19.82%-72.67% compared with the control. AFM showed that the myosin treated with EGC were small and evenly distributed. Microwave induced myosin to unfold and increased fluorescence intensity. EGC maintained the relative stability of the tertiary structures and delayed the increase of fluorescence intensity.Before microwave， low mass concentration EGC (20， 40 μg/mL) significantly increased α - helix content and maintained the stability of myosin secondary structure. After microwave， 20 μg/mL EGC maintained the stability of secondary structure. Molecular dynamics simulation showed that RMSF and RMSD value of myosin-EGC decreased， SASA decreased， secondary structure fluctuation decreased. It was found that myosin enhanced the stability of the complex under heating electric field by hydrogen bonding and hydrophobic interaction with EGC.