Abstract: Mixing in the rotating packed bed is extensively intensified and therefore is of great potential as a novel reactor for fast reactions such as reactive precipitation to synthesize nanoparticles. However, the mixing mechanism and the effect of mixing on reaction have not been elucidated yet. In this paper, a new model to simulate the turbulent reactive mixing between two non-premixed reactants flow through a single net grid is presented in order to help understand the mechanism and the effect of mixing in the rotating packed bed. The standard k-ε turbulent model is applied and the momentary closure for the covariance in the equations of species transfer which are similar to the methodology presented by Toor is set up. The mixing layer thickness, mean concentration and concentration covariance are simulated under the experimental conditions reported by Saetran et al and it is found that calculational values by the model are in good agreement with the experimental results with average deviation of mean concentration less than 10%.