The changes of digestibility， microstructure， amino acid composition， secondary structure and antioxidant activity of fermented wheat germ globulin (FWG) at different digestion stages were evaluated based on simulated gastric and intestinal digestion in vitro. The results showed that the digestibility of FWG decreased from 55.43% to 34.33% and 9.54%， respectively， and the average particle size decreased from 100 nm to 50-70 nm and 20-30 nm， respectively. The relative molecular weight of undigested protein was stable around 15 ku. After 2 h digestion， the release of total free amino acids of FWG was 2.05 times that of the original sample， and the contents of aromatic amino acids and branched amino acids were significantly increased. Lysine and valine， which were associated with the stability of α-helix and β-fold， were dissociated at this stage and disorder increases. The hydroxyl radical scavenging rate of FWG was significantly increased by 32.76% after gastric digestion， and ABTS free radical scavenging rate and DPPH free radical scavenging rate showed a decreasing trend during gastric digestion. After intestinal digestion， the total free amino acid content of FWG tended to be stable， and the order of secondary structure increased. ABTS free radical scavenging rate， which reflects the antioxidant capacity of hydrophilic peptides， first decreased， then increased and then decreased during intestinal digestion. Hydroxyl free radical scavenging rate was positively correlated with the relative content of hydroxyl amino acids， first decreased， then increased， then decreased and finally increased. The scavenging trend of DPPH free radical was closely related to the content of hydrophobic amino acids. This study provided a preliminary theoretical basis for further understanding the physicochemical properties and functional mechanisms of FWG during intestinal and gastric digestion.