Reasonable application of fertilizer ratio is an effective measure to control fertilizer application and reduce environmental pollution, which is a significant for the green development of agriculture. To clarify and evaluate the characteristics of tobacco leaves and improve the fertilizer utilization efficiency, the medium fertility soil was observed and the ¹⁵N tracer method were used and the effectiveness of no fertilization treatment T1, conventional fertilization treatment (1:0.5:2, CK), increasing potassium treatment (1:0.5:3, T2), increasing phosphorus treatment (1:1:2, T3) and increasing phosphorus and potassium (1:1:3, T4) treatments were designed in the field experiment to evaluate the effectiveness of yield and quality and nitrogen use efficiency of flue-cured tobacco with different P and K ratios with the same N conditions. The results suggested that: (1) The yield and economic income were increased under the treatment of increasing phosphorus and potassium with the same N conditions. The yield with the same N input were: T4 treatment > T3 treatment > T2 treatment > CK treatment > T1 treatment, and the economic income were: T4 treatment > T2 treatment > T3 treatment > CK treatment > T1 treatment. Compared with CK treatment, the yield and economic benefits in T2, T3 and T4 treatments increased by 11.81%, 3.48%, 20.72% and 9.66%, 1.17%, 19.81%,