The antioxidant activity in vitro experimental model method is adopted, with control of Vc and V_E, a comparative study of supercritical CO₂ extraction and petroleum ether extraction and supercritical CO₂ extraction after degumming and bleaching of three kinds of process technology for preparation of pepper seed oil antioxidant activity.The results show that the reduction ability of pepper seed oil and the hydroxyl radical, superoxide anion free radicals and H₂O₂ scavenging rate from high to low process followed by supercritical fluid extraction after degumming and bleaching, supercritical fluid extraction, petroleum ether extraction, DPPH free radical scavenging rate from high to low craft followed by petroleum ether extraction, supercritical fluid extraction, supercritical fluid extraction degumming and bleaching;Super critical fluid extraction after degumming and bleaching, supercritical fluid extraction, petroleum ether extraction of three kinds of technology to prepare the pepper seed oil on superoxide anion free radical IC₅₀ respectively 0.09 mg/mL, 0.13 mg/mL, 0.34 mg/mL. The IC₅₀ of hydroxyl radicals respectively for 0.98 mg/mL, 1.73 mg/mL, 2.19 mg/mL. The IC₅₀ of DPPH free radical respectively for 38.47 mg/mL, 10.82 mg/mL, 2.00 mg/mL; It is showed that the three kinds of process, pepper seed oil using supercritical CO₂ extraction after decolorization of the best.