The preparation of rice slurry is an important process in the processing of rice based fermented beverage, which has a great influence on the finished product quality. The three important processes of rice slurry preparation include: rice baking, liquefaction and saccharification were investigated by single factor experiment, and orthogonal experiments were used to optimize liquefaction and saccharification process. Results showed: the optimal baking conditions were temperature 180 ℃, time 15 min. Liquefaction conditions were 80 ℃, 140 min，thermostable α-amylase enzyme for 30 U/g. Saccharification conditions were 60 ℃, 6 h, glucoamylase dosage for 300 U/g. Under these condition, rice slurry tasted light fragrance of rice, the DE value and soluble solid content（TSS） were 99.86%, 9.4%, respectively.