Catechol is a major cell growth inhibitor in lignocellulose hydrolysate， with strong toxicity， and can inhibit the growth and fermentation performance of Saccharomyces cerevisiae during subsequent alcohol fermentation. The effects of catechol on the physical and chemical properties of Saccharomyces cerevisiae GGSF 16 were studied. The results showed that when the concentration of catechol was 1.2 g/L， the growth and metabolism of Saccharomyces cerevisiae cells were significantly inhibited， resulting in slower glucose consumption time and longer ethanol fermentation cycle， and lower ethanol production rate. The membrane permeability of yeast cells was significantly changed， and the content of nucleic acid and protein in the cells was 2.50 and 2.01 times higher than that in the control group. The content of trehalose， a stress metabolite in cells， increased significantly by 2.89 times. In addition， in order to resist the oxidative damage of cells， the content of intracellular GSH decreased significantly by 70.63%. Scanning electron microscope showed that after treatment with catechol， the cell wall and cell membrane of smooth and full yeast cells were damaged， and there were cavities， a large number of torn fragments and adhesion between them. The cells lost their protective effect and died. This study preliminarily clarified the damage and toxicity mechanism of phenols on Saccharomyces cerevisiae， and provided a reference for further revealing the inhibitory effect of lignocellulose hydrolysate on Saccharomyces cerevisiae.