Based on the similarity of the unstable diffusion equation and the transient heat conduction equation in mathematical form, this paper studied the thermal analysis module of the software Ansys to simulate the migration process of chemical compositions from food packages to food. The related parameters of diffusion process were substituted for those of heat conduction in Ansys, simulating the migrating process from monolayer packaging materials to food through building a 2D solid model and using a plane55 element type. And the results were compared with those of the data simulation and the existing migration analysis software. The results showed that the curve by data simulation fit well with that by the existing migration analysis software Akts SML, however, the curve by the finite element software Ansys did not completely fit with the former two curves in early stage, while it highly fit in late stage. As Ansys can simulate the diffusion process in food after migration, the analysis method of Ansys is worthy of further research.