To investigate the mechanism of oxidative stress response during high-density culture of Saccharomyces cerevisiae PY01， transcriptomic analysis was performed after 2 h of oxidative treatment (6 mmol/L H2O₂). The results showed that 393 differentially expressed genes (DEGs) were identified， and based on GO annotation and KEGG enrichment analysis， the identified DEGs were involved in metabolic (e.g. amino acid metabolism， carbohydrate metabolism and energy metabolism)， genetic information and cellular processes (peroxisomes) and other pathways. Under oxidative stress， yeast scavenges ROS by enhancing several antioxidant enzymes， including SOD2， SRX1 and so on， yeast also generates more energy by enhancing glycolysis and the TCA cycle to adapt to oxidative stress， repair damaged proteins， and transport of DNA or maintain metal ions. Meanwhile， molecular chaperones and proteases associated with general stress responses are upregulated. It was shown that the response of Saccharomyces cerevisiae PY01 to oxidative stress is a complex， integrated regulatory network. The discovery and understanding of the mechanism of Saccharomyces cerevisiae PY01 in response to oxidative stress has laid the theoretical foundation for designing control strategies for efficient cultivation of yeast， improving the resistance of the strain， and promoting the use of active yeasts in the production of modern fermentation industries such as fruit wines and other biological products.