Abstract: Based on mixture theory and experimental crystal morphology,a numerical continuum model describing momentum,heat and mass transport phenomena occurring during Falling Film Crystallization Process is set up.One distinct characteristic of the present model is that there is an irregular two-phase mushy region existing between the liquid and solid phases.With Falling Film Crystallization going on,the solid fraction within the mushy region keeps increasing until complete solidification and the mushy region as well as solid region keeps in growing into the liquid region,The mushy region provides various locations for impure inclusion,which may be one of the practical reason for inclusion occurring.In order to model the coupled momentum, heat and mass transport in porous mushy region,the theory of transport phenomena in porous media is introduced and unsteady Darcy equation with Brinkman extension is adopted.Further more,Van Driest-modified Prandtl’s mixing length model is used to reflect the turbulent transport phenomena occuring in the liquid region.