This study aimed to determine the efficiency of ultraviolet (UV)-LED cold light treatment on the degradation of aflatoxin (AF)B1 in peanut oils. The peanut oil samples obtained from different places in China and abroad were determined for AFB1 degradation efficiency of the UV-LED cold-light irradiation method. The degradation products were analyzed by ultra-high performance liquid chromatography coupled to quadrupole orbitrap high-resolution mass spectrometry (UPLC-Q-Exactive MS). The results indicated that the AFB1 content in all peanut oil samples decreased rapidly after 5 min of irradiation. Four main photodegradation products (C₁₈H₁₆O₇, C₁₇H₁₄O₇, C₁₇H₁₄O₇, and C₁₇H₁₄O₈) were identified using the established LC-MS method. Their chemical structures were postulated based on the LC-MS data. Also, the degradation pathways were proposed based on the data obtained. Oxidation and reduction reactions were mainly responsible for AFB1-decomposition. The reactions occurred at the furan and lactone rings. These findings demonstrated that UV-LED cold-light irradiation was an effective method for treating AFB1- contaminated peanut oil.