Steam explosion conditions of sugarcane bagasse were studied,and sugarcane bagasse products after steam explosion pretreatment were identified by HPLC. At the same pressure of the steam explosion,the degraded products were harmful to enzymatic hydrolysis and fermentation creased with extension of pressure holding time. Based on the laboratory research,scale-up fermentation experiments in 50 L fermentor were further carried out. After 48 h fermentation,ethanol concentration 6. 17%( φ) was obtained with 27. 09%( ω) solid concentration of hydrolysate,indicating that sugarcane bagass was suitable for conversion into ethanol.