It will spend 30 minutes completely gelatinizing corn starch in hot water,whose temperature is 95℃.It will consume a lot of energy and lead to the sizing progress ineffectively.Recently it is reported that adding sodium hydroxide solution into corn starch was applied in improving the efficiency of preparing starch.However,sodium hydroxide will damage the equipment or preparing corn starch.As we all know,ammonium bicarbonate belongs to weak base,which will affect the equipment much smaller.In the paper,ammonium bicarbonate will be applied in improving the efficiency of preparing corn starch.