In the test，the starch syrup was obtained by extrusion and enzyme hydrolysis of corn meal．With the aid of the combination design of quadratic orthogonal rotation，the influential rules of extrusion factors to DE value was demonstrated，and the technology conditions of liquefaction and saccharification were established by orthogonal design. The results showed that when heating temperature of extruded was set to 64.2～70.9℃，rotation speed of extruder was 193～202r/min，moisture of material was 18.43%～19.66%，die hole aperture of extruder was 12.2～13.0mm，and the enzyme hydrolysis technology according to the ratio between water and material was 3.0mL/g，liquefaction was 20 min，saccharification was 40min，the DE value was about 40.80%. 