Steam-exploded technique was applied as corn stalk pretreatment to biogas enhancement in the process of anaerobic digestion. The effects of steam pressure, retention time in anaerobic digestion processes of steam-exploded corn stalk were investigated. The results showed that the steam-exploded corn stalk is more easily to be digested than the unpretreated. The ability to be digested of the steam-exploded corn stalk improved as the increase of steam pressure, the biogas production are greatly enhanced in the range of 34 to 67.36 percent. The biogas production can reach 304.72 mL/g of dry corn stalk with the pressure of 3.0 MPa and the retention time of 90 s. The start-up time and the period of anaerobic digestion of steam pretreated corn stalk were all significantly shortened.