By adopting the semiconductor thermoelectric power generation technology, the recovery of the waste heat can be achieved in the radiator of the electric locomotive cooling system, thus making it possible to convert the low-grade energy contained in the radiator into the electric energy and then store it in the storage battery. Based on the recovery and conversion of the waste heat from the electric locomotive cooling system as well as the analysis of the properties of the thermoelectric power generation, a model has been established of the thermoelectric power generation system. In view of the instability of the output voltage of the thermoelectric power generation system system, a stable voltage circuit has thus been designed. The feasibility of the design has been verified by Matlab/Simulink simulation analysis, which helps to lay a foundation for future battery energy storage.