高低温工况是影响氢燃料电池长期密封可靠性的重要因素。温度影响下橡胶件的密封性能不仅与材料的宏观特性相关，也受到其表面微观粗糙形貌接触状态的影响。针对氢燃料电池“橡胶-金属”粗糙密封界面，本文建立同时具有密封件微观形貌和宏观基体特征的多尺度接触模型，通过研究交变温度下多尺度接触模型的力学状态，实现氢燃料电池复杂温载下的界面泄漏率多尺度建模，并通过21天高低温实验以及界面泄漏率测量结果，验证了多尺度模型对于预测电池长期密封性能的有效性。基于多尺度接触模型的研究表明，氢燃料电池“橡胶-金属”粗糙密封界面的最大接触应力随交变温度循环次数的增多而不断上升，粗糙密封界面的实际接触面积不断减小、泄漏通道数量不断增多，进而使得氢燃料电池密封性能逐步退化，电池界面密封性能在21天内共下降了37.08%，而第7天至第21天相对平稳下降了9.62%。通过与实验值对比，相较于传统宏观研究方法，多尺度模型的预测结果与测量结果吻合程度更高。

High-low alternating temperature condition is an important factor affecting the long-term sealing reliability of hydrogen fuel cells. The sealing performance of rubber gaskets under temperature loads is not only related to the macroscopic characteristics of the material, but also directly affected by the contact state of rough sealing interface which contains microscopic protrusions. The multi-scale contact model, which contains the morphology feature under micro-scale and the material properties under the macro-scale, for the rough sealing interface between the rubber gasket and the metal plate in hydrogen fuel cells has been established in this paper. By studying the contact state of the multi-scale model under alternating temperature loads, the interfacial leaking of fuel cells under complex temperature loads has also been modeled. The long-term sealing reliability of the multi-scale model has been verified by measuring the interfacial leakage rates of an interfacial sealing device that has withstood the high-low alternating temperature load for 21 days. It can be found through researching the contact state of sealing interface based on multi-scale method that the maximum contact stress of the rough fuel cell sealing interface increases continuously with the increase of alternating temperature cycling times, meaning in a decrease in the actual contact area and an increase in leaking channels. The sealing performance of hydrogen fuel cells decreases by 37.08% within 21 days, with a decrease of 9.62% from the 7th to the 21st day, which is closer to the measured values.