Abstract: A mathematical model was developed introducing the dual-vector magnetic potential into it for simulation of induction heating, based on FEM and the software ANSYS. Discusses the key technological problems and the ways to solve them, such as the coupling of temperature field with electromagnetic field in FEA and the dependence of physical parameters of workpiece materials on temperature. The induction heating process of the chucking for electro-slag furnace was analyzed to find out the temperature distribution of chucking and the variation of time-dependent temperature. The results showed that the maximum temperature is mainly concentrated on the surface layer of chucking and, what's more, the core part of chucking is basically unheated. Simulation results were verified in accordance to the practical application results on the whole.