In this work, the conjugate heat transfer during the freezing process of salmon flesh was investigated by CFD simulation method. A mathematical model was developed to model the conductive heat transfer inside of a foodstuff during the freezing process. The latent heat of the liquid water solidification process is considered using the concept of effective heat capacity. The developed model was integrated into the CFD simulation model. The CFD model is validated by comparing numerical observation with the data measured from the freezing process of a single salmon fillet in a laboratory-scale freezing chamber. Afterward, the CFD simulation is performed to describe the freezing process in a large-scale freezer. The numerical results show a remarkable temperature maldistribution inside the chamber resulting in a non-uniform freezing time. It implies that the CFD simulation can be conducted to optimize the design of the large-scale freezer in the future.