In order to increase corn straw degradation, the straw was kept in the combined solution of 15% (w/w) lime supernatant and 2% (w/w) sodium hydroxide with liquid-to-solid ratio of 13: 1 (mL/g) at 83.92 degrees C for 6 h; and then added with 3% (v/v) H2O2 for reaction at 50 degrees C for 2 h; finally cellulase (32.3 FPU/g dry matter) and xylanase (550 U/g dry matter) was added to keep at 50 degrees C for 48 h. The maximal reducing sugars yield (348.77 mg/g) was increased by 126.42% (P < 0.05), and the degradation rates of cellulose, hemicellulose and lignin in pretreated corn straw with enzymatic hydrolysis were increased by 40.08%, 45.71% and 52.01%, compared with the native corn straw with enzymatic hydrolysis (P < 0.05). The following study indicated that the combined microbial fermentation and enzymatic hydrolysis could further increase straw degradation and reducing sugar yield (442.85 mg/g, P < 0.05). (C) 2015 Elsevier Ltd. All rights reserved.