Abstract: To investigate the effects of wet-bulb temperature during the yellowing stage on the curing quality and metabolite changes of tobacco leaves, this study used the middle leaves of Cuibi-1 (CB-1) as experimental materials and set the wet-bulb temperatures of 37~37.5℃ - 36~37℃ - 36~37℃ (T1 treatment), 37.5~38℃ - 38~39℃ - 38℃ (T2 treatment), and 38℃ - 39~40℃ - 36~37℃ (T3 treatment) during the early, middle, and late stages of yellowing. The chemical composition and taste quality of the cured tobacco leaves were evaluated, and differential metabolites between the three curing treatments were identified throughout the yellowing and color-fixing stages using non-targeted metabolomics technology. The results showed that, compared with the T1 and T3 treatments, the T2 treatment yielded the most balanced chemical composition, including nicotine, total sugar, reducing sugar, chloride ions, sugar-alkali ratio, chlor-alkali ratio, and potassium-chloride ratio. It also achieved the highest scores for style and quality characteristics, with a more pronounced aromatic style and superior sweetness, aroma quality, and overall sensory evaluation. Metabolomics analysis identified 4327 metabolites in CB-1 tobacco leaves across the three curing treatments. From the mid-late yellowing stage S4 to the mid color-fixing stage S6, more than 2000 metabolites differed among the three treatments. The greatest number of differential metabolites was observed in the late yellowing stage S5, indicating that this stage is critical for the formation of quality differences caused by variations in wet-bulb temperatures. Significant changes were observed in key metabolites, including organic nitrogen compounds, carbohydrates, flavonoids, alkaloids, terpenes, and lipids, during the curing process. Compared with T1 and T3, the T2 treatment exhibited more complete conversion of organic nitrogen compounds in the late stage of color-fixing. Carbohydrate decomposition produces more sweet substances such as melibiose, catalpol, galacturonic acid, L-gulose, and mannotriose, contributing to its clear and sweet style under the T2 curing treatment. T2 treatment generates greater amounts of glabridin, betanin, aconine, and acetylvalerenolic acid, which underlie its aroma classification and aroma characteristics. Furthermore, the accumulation of reserpine, oripavine, baptifoline, ergotamine, and alpha-narcotine during the late yellowing stage under T2 treatment was associated with enhanced smoking vigor.