The paper firstly introduces the principle and mode of electromagnetic induction heating. Accordingly the basic equations of electromagnetic field and temperature field in the heating material are derived from Maxwell's equations and heat conduction differential equations. Then give an example of the electromagnetic induction heating. With the application of ANSYS software, the one-dimensional finite element model of the heating material is built. And numerically simulate it by the means of the electromagnetic field and temperature field coupling in the ANSYS software. The influence of the material's physical parameters changing with the temperature and significant skin effect in the electromagnetic induction heating are considered. So the results are correct and reliable.