A three-dimensional finite difference method (FDM) model of grinding temperature field for carbon fiber reinforced plastics (CFRP) was established, based on the homogenization of the thermal properties of the CFRP material. The effect of the fiber direction on grinding temperature distribution at different workpiece velocity was numerically simulated and analyzed. It is found that the effect of the fiber direction on grinding temperature field is remarkable in lower workpiece velocity but unapparent in higher workpiece velocity due to the anisotropy of CFRP material and the velocity of moving heat source. More than 230 °C surface grinding temperature, which will badly damage CFRP performance, may be produced in dry grinding according to the simulated analysis. During grinding the heat affected zone of CFRP is about 0.22 mm in depth direction. Furthermore, experimental results are well in agreement with those of the theoretical analysis.