It is well known that components with dissimilar compatibility factors cannot be combined by segmentation into an efficient thermoelectric generator, since each component needs a unique optimal current density. Based on the complex variable method, the thermal-electric field within a bi-layered thermoelectric composite has been analyzed, and the field distributions have been obtained in closed-form. Our analysis shows that current refraction occurs at the interface, both the refraction angle and current density vary with the incidence angle. Further analysis proves that the current densities in two components can be adjusted independently by adjusting the incidence current density and incidence angle, thus the optimal current density can be matched in both components, and the conversion efficiency can be significantly increased. These results point to a new route for high efficiency thermoelectric composites.