The fucoxanthin was used as raw material to investigate the antioxidant activity of fucoxanthin on fish oil and lard. The results showed that fucoxanthin could effectively inhibit the formation of malondialdehyde （MDA） in fish oil and pork in the oxidation model， and the highest inhibition rate was 78.1% and 80.9% compared with the blank group. The results showed that the electron spin resonance spectroscopy technique was used to investigate the scavenging effect of fucoxanthin on lipid free radicals in fish oil， corn oil， linoleic acid and linoleate models. When the fucoxanthin mass concentration reached 100 ng/mL and accelerated oxidation for 3 h， the inhibition rate of lipid free radicals in the fish oil model and the corn oil model was （64.46±6.46）% and （57.4±5.15）%； the fucoxanthin mass concentration was 300 ng/mL， and the accelerated inhibition of lipids in the linoleic acid model and the linoleate model was（75.24±7.32）% and （66.9±1.06）%. This study provides a theoretical basis for the application of fucoxanthin in the field of health foods and food antioxidants.