The treatment of corn starch by adding enzyme extrusion technology as material to produce isomalto-oligosaccharide. With the sum content of isomaltose (IG₂), panose (P) and maltotriose (IG₃) as the yield index of isomalto-oligosaccharide, the parameters were optimized by orthogonal experiment, and the optimum processes for production of ismalto-oligosaccharide from corn starch with enzymatic extrusion were as followed: the extrusion temperature 95 ℃, the water content 45%, and the amount of enzyme 0.8%. And the yield of the ismalto-oligosaccharide with the highest yield could reach over 35%.