This research aimed to address the issue of aflatoxin B (AFB) contamination, which posed severe health and economic consequences. This study involved exploring unique species resources in the Qinghai-Tibet Plateau, screening strains capable of degrading AFB. UPLC-Q-Orbitrap HRMS and NMR were employed to examine the degradation process and identify the structure of the degradation products. Results showed that YUAD7, isolated from yak dung in the Qinghai-Tibet Plateau, removed 91.7% of AFB from TSB-AFB medium with an AFB concentration of 10 μg/mL (72 h, 37°C, pH 6.8) and over 85% of AFB from real food samples at 10 μg/g (72 h, 37°C), exhibiting strong AFB degradation activity. YUAD7's extracellular secretions played a major role in AFB degradation mediated and could still degrade AFB by 43.16% after boiling for 20 min. Moreover, YUAD7 demonstrated the capability to decompose AFB through processes such as hydrogenation, enzyme modification, and the elimination of the -CO group, resulting in the formation of smaller non-toxic molecules. Identified products include CHO, CHNO, CHO, CHNO, with a structure consisting of dimethoxyphenyl and enoic acid, dimethyl-amino and ethyl carbamate, polyunsaturated fatty acid, and aminomethyl. The results indicated that YUAD7 could be a potentially valuable strain for industrial-scale biodegradation of AFB and providing technical support and new perspectives for research on biodegradation products.