<p>Automotive airbag electrical connectors are subjected to simultaneous temperature and vibration during vehicle service, and their contact degradation mechanism under combined thermal-vibration stress is important for reliability evaluation. In this study, an automotive airbag electrical connector was investigated, in which the receptacle was made of beryllium bronze, the pin was made of stainless steel, and both contact members were coated with nickel/gold. Accelerated thermal aging at 160&#xa0;°C and combined thermal-vibration accelerated testing at the same temperature were conducted to obtain degraded contact samples. Based on the evolution of contact resistance and the analysis of surface morphology and elemental composition before and after testing, the contact interface under combined thermal-vibration stress showed more severe film damage, more obvious appearance of Ni-related features, and local detection of substrate elements, indicating a markedly accelerated degradation process. The results show that contact degradation under combined thermal-vibration stress remains primarily governed by oxidation corrosion, while fretting wear is superimposed on the oxidation process. At nearly equal accelerated exposure durations, the mean contact-resistance increment under the combined condition was 1.068 mΩ, approximately 3.32 times the value of 0.322 mΩ measured under thermal-only exposure. As a result, under nearly the same accelerated exposure time, the samples subjected to combined thermal-vibration stress exhibited more severe surface damage and more obvious Ni-related features and local detection of substrate elements. These findings provide technical support for contact degradation analysis, test evaluation, and early risk identification of automotive airbag electrical connectors under thermal-vibration service conditions.</p>