Based on the finite element software COMSOL Multiphysics 4.3b, a temperature field model for an aluminium/stainless steel composite third rail and a copper impregnated carbon collector shoe contact with coupling of joule heat and friction heat was established. A method of coupling the two kinds of heat was developed, the temperature fields were calculated, and the maximum coupled temperature change under different electric current, normal forces, sliding velocities and sliding distances were studied. The results show that the temperature distribution expands around the contact area in a descending tendency at positions closer to the electric contact area and the temperature gradients are higher; the maximum coupled temperature increases with an increase of electric current; with an increase of normal force, the maximum coupled temperature initially decreases then increases; the maximum coupled temperature increases initially then gradually becomes stable with an increase of sliding distance; an optimal normal force range exists in frictional sliding with an electric current, at which the maximum coupled temperature is at its lowest; joule heat and friction heat are competitive with each other. When normal force is lower, the joule heat becomes the main heat source, but when normal force is greater, mechanical friction heat becomes the main heat source
