At present，there are many planar workpiece grinding thermal models. However，they cannot be applied to the calculation of the tooth-like surface grinding. Therefore，based on the gear involute arc fitting，the moving heat source method and the imaging method are combined in this work to deduce the analytical thermal model of grinding teeth with large flat wheel，which can be used to calculate the temperature of grinding gears. The simulation of grinding process is made based on ANSYS and compare to the established quasi-steady-state analytical thermal model. The comparison results show that the value of grinding temperature predicted by numerical model has well agreement with the analytical model and some errors exist in the contact area and the junction between contact area and non-contact area. The deduced analytical thermal model can be used to analyze the temperature of processing tooth-like curve workpiece.