Thermoelectric devices have significant thermal stress and deformation affected by the temperature difference, which affecting their working stability and life span. In this paper, thermoelectric pairs are allocated in the x, y and z directions respectively to a single thermoelectric pair. And the maximum stress and deformation in all schemes are calculated by the finite element analysis. The results show that the interaction of the thermoelectric pairs in the z direction makes the maximum stress and the deformation decrease. The interaction of the z-direction thermoelectric pairs is beneficial to the reliability of thermoelectric devices. When designing thermoelectric devices, reducing the number of arrangement in the x, y directions and increasing the number of arrangement in the z direction can effectively improve their working stability and life span.