Black rice effervescent tablets were prepared by acid and alkali separation wet granulation process， and the product formula of black rice effervescent tablets was optimized by orthogonal test. The results showed that the best puffing conditions was moisture content 16%， extrusion temperature 130 ℃， 28 Hz for the screw rotation， and the optimal formula of black rice effervescent tablet was composed of 7.5% puffing black rice powder， NaHCO3 and citric acid mass ratio of 1 ∶ 1， 8% xylitol， in order to improve the taste， also added 0.3% sucralose， 32.2% maltodextrin. Under the conditions， the effervescent tablets were weakly acidic and could be rapidly disintegrated. The amount of foam was 12.6 mL/g， and the solution was purplish red with certain precipitation.