Production process for starch sugar

The invention discloses a starch sugar production process, which comprises steps of rice pulverizing, liquifying, deslagging, saccharifying, decoloring, ion exchanging, concentrating, packing or the like. According to the invention, a high temperature high pressure spraying method is applied to a regulated starch milk charged with high temperature resistant a-amylase, so that a hollow cylindrical thin-film is formed by the starch milk under high temperature high pressure condition in the ejector, Van der Waals force between starch molecule is broken, which is beneficial for biochemical action of high temperature resistant a-amylase, the a-1,4 glycosidic bond of starch chain is rapidly cut. The problem of starch milk thorough hydrolysis is solved; temperature of liquefier is lowered to the physico-chemical temperature through two times of flash evaporation, concentration of sugar liquor is enhanced from 33% to 37%, and a large amount of steam is saved for the concentration step; by the improvement of the one-time deslagging and the one-time slag washing, not only 10% of sugar content is recovered from the sugar slag for enhancement of yield, but also protein content in the sugar slag is enhanced for earning increasing; by adopting counter current carbon discharging decoloring process, not only process requirement is ensured, but also the carbon cost is saved.