Fracture and block flaking off caused by surface micro-cracks are the main failure mode of CuW contact. Finite element method was applied to analyze temperature and stress distribution of CuW contact by thermo-elastic effect under arc thermal load considering the arc heat distribution in time and space, temperature dependent material properties and latent heat at high temperature. According to the thermal stress distribution, cracks nucleation process and places were predicated under driving force on component, thus providing foundation for the damage analysis of contact.