Abstract: To effectively address the thermal runaway phenomenon in energy storage systems and ensure the safe operation of power systems, this paper conducts research on the multi-stage blocking design of thermal runaway in electrochemical energy storage systems. Based on the consideration of the heat absorption and release behavior of individual cells in the system, this paper establishes a thermal runaway propagation model. Based on the heat transfer process, a thermal expansion protection structure is designed and combined with jet guidance technology to achieve efficient anti-diffusion treatment of thermal runaway. From the perspective of electrical safety, a multi-level power safety isolation mechanism is established to conduct a multi-level blocking design for thermal runaway in energy storage systems. The practical application of this method shows that it can achieve multi-level blocking of system thermal runaway and prevent the spread of thermal runaway phenomena.