High-quality corn starch can be used, and maltose-based syrup can be prepared through various enzymatic hydrolysis. The product is a colorless, transparent and viscous liquid with clear plastid, transparent texture, mild and pure taste, low sweetness, malt flavor, high boiling temperature, low freezing point, anti-crystallization and many other advantages. It is often used in jam and jelly to prevent the crystallization of sugar, and high malt has good expansibility, so it is also widely used in bread and jelly. In addition, high maltose syrup does not depend on human islet metabolism, blood sugar rises slowly, and its calorific value is low, which has certain health care function for cardiovascular patients, diabetics and obese people.