The electrophilic components in Xiaoheiyao were knocked out by GSH functionalized magnetic nanoparticles (GSH-MNPs) and characterized by LC-MS analysis, and the effect and mechanism of the electrophilic components in Xiaoheiyao for reducing lipid accumulation and oxidative stress in hepatocytes were evaluated, based on free fatty acid (FFA)-induced HepG2 cells. The ethyl acetate fraction was determined as the most electrophilic components-enriched part of Xiaoheiyao. At the concentration of 0.5~2.0 μg/mL, the petroleum ether, ethyl acetate and water fractions of Xiaoheiyao exhibited the activities of decreasing hepatic lipid accumulation and ROS production, in which the ethyl acetate fraction showed the best activities. The ethyl acetate fraction of Xiaoheiyao decreased the intracellular levels of TG and TC while increased the activities of the antioxidant enzymes. After electrophilic components in ethyl acetate fraction were knocked out by GSH-MNPs, the activities for the decreasing TG and TC levels and increasing the activities of antioxidant enzymes were significantly compromised. After treated with ethyl acetate fraction, the expression of Nrf2 and its downstream genes NQO1, HO-1 and GCLC were upregulated. Moreover, the expression of genes for lipid synthesis, including SREBP1c, ACC1, and FAS, were found downregulated, while the expression genes PPARα and CPT1A, involved in lipidolysis, were upregulated. After the electrophilic components were knocked out, the effects of the ethyl acetate fraction on regulating lipid metabolism and redox-related genes were significantly reduced. Seven mass features were found by LC-MS and concluded as electrophilic components when comparing the ethyl acetate fractions before and after treated with GSH-MNPs. The mechanism of electrophilic components in Xiaoheiyao improving the hepatic steatosis induced by FFA was associated with the regulation of the genes related to lipid metabolism and redox.