Based on finite element simulation, the temperature field model for the frictional pair of third rail and collector shoe under the coupling of contact resistor thermal and friction thermal was established. The method of coupling the two kinds of thermal was given in detail, the temperature field was calculated, and the maximum coupled temperature changing under different electric current, velocity, and displacement of the model was studied. The results show that the temperature raising effect of friction thermal and contact resistor thermal is different. In the process of mechanical friction without electric current, the highest temperature is in the contact center line, the temperature distribution expands around the contact zone in descending tendency. But in couple condition, the temperature distribution with electric current expands around the contact point in descending tendency. In the two conditions, the temperature gradients are all becoming smaller. The maximum coupled temperature increases with the increasing of the electric current, and decreases with the increasing of the velocity under the constant displacement and normal force. The maximum coupled temperature increases linearly with the increasing of displacement under constant electric current, velocity and normal force.