Umbilical cable is composed of electronic cables, optical cables, steel tubes and structural strengthening components, which can be regarded as a key industrial equipment integrating mechanical and electronic functions. Especially, when it is oriented at the power supply with a relatively high rated voltage, the power transmission will produce a large amount of heat with the sectional temperature rising up, which impacts on the material performance and mechanical responses of the cable and even the whole umbilical. Therefore, the thermo-elastic analysis is the critical technology in the cross-sectional design of umbilical cable. Analytical and numerical methods are proposed to conduct the thermo-elastic analysis of the cross-section. Firstly, the steady-state thermal analysis of cross-section of the umbilical cable is implemented, and the thermal field distribution with different cable ampacity is obtained. Then, the thermo-elastic coupled analysis of the cross-section is presented. It is found that the results are quite different from that of static mechanical analysis, which provide a helpful guide for the design of umbilical structures.