Distillers grain (DG) is an abundant and low-cost lignocellulosic biomass. The objective of paper is to compare the influence of different acids on hydrolysis of DG and select the best acid. The results indicate that sulfuric acid is the most effective acid, and the optimum hydrolysis conditions are temperature 100°C, sulfuric acid concentration 2.0%, solid-liquid rate 1:12 (w/v), time 3.0 h. Under these conditions, the concentration of reducing sugar (RS) and xylose are 43.69 g/L and 35.16 g/L, respectively. The bioethanol production is around 11.82 g/L, which corresponds to 77.12% of theoretical yield and 0.14 g/g of consumed sugar.