Through testing the characteristics of temperature difference power supply model, a multi-stage temperature difference power supply array circuit model considering package thermal resistance and contact thermal resistance is presented. The model not only considers the influence of the impedance temperature and the actual temperature difference in the equivalent circuit; The influence of contact thermal resistance between adjacent ceramic contact surfaces in temperature difference modules on temperature difference power generation modeling is also considered. Furthermore, the traditional temperature difference power array circuit model is improved and the modeling accuracy is improved. The accuracy of the improved resistance modeling is demonstrated by comparing the Matlab/Simulink simulation with the experiment, and the feasibility and validity of the model are verified. The simulation results show that the error between the proposed model and the experiment is small, which can well reflect the characteristics of the temperature difference power generation module.