Abstract: A split-plot field experiment was conducted in southern Anhui. Three nitrogen levels (97.5, 112.5 and 127.5 kg/hm²) and three planting densities (120 cm×60 cm, 120 cm×55 cm and 120 cm×50 cm) were tested to analyze their effects on the growth, development, physicochemical properties, yield and quality of tobacco leaves. The results showed that N₂D₂ treatment (nitrogen application rate 112.5 kg/hm²+planting density 120 cm×55 cm) significantly promoted the accumulation of total sugar and reducing sugar, improved the chemical composition coordination of the upper tobacco leaves and the single-leaf weight. Stem holdup were controlled within a reasonable range. The comprehensive score of the appearance and sensory quality evaluation of tobacco leaves was relatively high, and the overall performance in optimizing the yield and quality of upper tobacco leaves was superior. Therefore, it is suggested that the flat tobacco fields in southern Anhui adopt a combined treatment of moderate nitrogen application and medium planting density. Ensuring the tobacco leaf yield in the flat tobacco fields of southern Anhui while significantly improving the quality of tobacco leaves and safeguarding the economic benefits of tobacco farmers.