Disclosed is a preparation method of grain drink, which includes the steps of: (1) providing an aqueous solution of grain powder； and (2) performing a hydrolysis on the aqueous solution of grain powder in the presence of enzymes so as to obtain a grain drink, wherein the enzymes contain glucoamylase and <；alpha>；-amylase. Based on 100 parts by weight of the grain powder in the aqueous solution, the weight of the <；alpha>；-amylase is less than 0.1 parts by weight and greater than 0.02 parts by weight. The grain drink prepared by the present preparation method is provided with better palatability (the viscosity is moderate and the flavor is better).一種穀物飲品的製備方法，包含下列步驟：(1)提供穀物粉水溶液；及(2)於酵素的存在下，使該穀物粉水溶液進行水解反應，以得到該穀物飲品，其中，該酵素含有葡萄糖澱粉酶及α-澱粉酶，且以該穀物粉水溶液中的穀物粉之重量為100重量份計，該α-澱粉酶的重量小於0.1重量份並大於0.02重量份。本發明製備方法所製得的穀物飲品具有較佳的嗜口性(黏度適中且風味較佳)。
