Research on the simulation and calculation of the temperature field of friction plate in brake is one of the main references for constructing a frictional material couple. The friction heat generates on the real contact area, so the distribution of the friction heat is asymmetry and localized. In this study, the effects of real contact area on the surface temperature were investigated. Then the mathematical model of the two-dimensional unsteady temperature field of local contact area is presented. The simulation of the model for Cu-based wet friction plate indicates that the local contact has an essential influence on the surface temperature and the maximal contact temperature; the mathematic model of local contact temperature field can be used to predict the critical sliding velocity and allowable rate of energy absorbed.