Abstract: To consider the thermal constraints under harsh working conditions that are lack in traditional energy management strategies, an energy redistribution strategy was proposed. Firstly, a diesel-electric hybrid system model with a thermal management subsystem was built and verified, determining the weight coefficient of each cooling capacity index based on neighborhood component analysis. Then a comprehensive thermal evaluation system was developed to provide a reflection for the system thermal state. Combined with the thermal evaluation system, an energy redistribution method based on the momentum gradient descent method was proposed. Taking two typical working conditions of high altitude and battery cooling system deterioration as examples, a real-time simulation analysis of the energy redistribution strategy was carried out. In both working conditions, the strategy can significantly improve the thermal state of the system by sacrificing less comprehensive fuel consumption and ensure the reliable operation of the vehicle. The results show that the proposed energy redistribution strategy with the consideration of thermal constraints can provide a better result.