A mathematic model was established, which described thermal-electric-structure coupling of AgNi10 contact material during DC closed stage. Distributions of temperature field, electric field and stress-strain field were calculated by finite element method. In the calculation process, the sequential coupling mode was adopted. Physical and mechanical properties varying with the temperature and contact resistance were taken into account. And real boundary condition was also considered. The results show that current density is of heterogeneous distribution along the contact interface, and ring heat source is generated; thermal stress concentration zone moves from the contact center to the interior because of effects of thermal-electric-structure coupling; meanwhile, the thermal stress concentration zone appears on the edge of contact interface, and it is easy to become crack source, which is consistent with the experiment.