A new system for improving the growth of KDP crystal with rotary flow field and stationary crystal is proposed. The 3D numerical simulation for flow and mass transfer shows that the rotation rate is the key factor that has a significant effect on the surface supersaturation and surface homogeneity. Especially for the high rotation rate, higher surface supersaturation and better surface homogeneity can be gained. Bulk supersaturation and inlet velocity also affect surface supersaturation and surface homogeneity to a certain extent. The surface shear stress increases with enhancing the rotation rate or the inlet velocity. The optimization for the configuration has also been discussed, which is helpful for the surface homogeneity. (C) 2011 Elsevier B.V. All rights reserved.