Abstract: To clarify the nitrogen-potassium fertilization ratio for flue-cured tobacco in Weng'an tobacco-growing areas, this study utilized Xiangyan 7 as the test material. A dual-factor（nitrogen and potassium application rates）orthogonal experiment with three levels and nine treatments was designed to investigate the effects of different N-K fertilization ratios on tobacco yield and quality. A fuzzy comprehensive evaluation method was applied to assess the appearance quality, physical indices, chemical composition, and smoking quality of tobacco leaves under various N-K ratios, aiming to provide guidance for nitrogen and potassium fertilization practices in the region.The results showed that the quality index of flue-cured tobacco under N₃ treatment was higher than that of other treatments.In terms of agronomic and economic traits, high-nitrogen treatments（N₃）significantly increased plant height, maximum leaf length, maximum leaf width, and the proportion of premium-grade tobacco leaves across different potassium application levels. For appearance quality, the quality index improved with increasing nitrogen under high-nitrogen treatments, with N₃K₃ achieving the highest score（80）. Chemical composition analysis showed higher usability indices for N₁K₂, N₃K₂, and N₃K₃. In conclusion, the fertilization regimen of applying an additional 15 kg·ha⁻¹ pure nitrogen combined with 20% K₂O（N₃K₃）in Weng'an tobacco-growing areas enhances agronomic traits during field growth, optimizes economic indicators, yields the highest appearance quality score, improves physical properties, achieves balanced chemical composition, and provides optimal sensory quality, demonstrating the most effective approach for improving both economic performance and tobacco leaf quality.