In order to improve the fertilizer utilization efficiency and reduce the application of chemical fertilizers， a field experiment was conducted with three replications in six treatments in Anhui Wannan in 2018.Effects of different ratio of water soluble fertilizer topdressing 50%，60%，70%，80% on yield and quality of tobacco leaves under the conditions of reducing nitrogen fertilizer by 13% and phosphorus and potassium fertilizer by 30% were analyzed.The results showed that(1)When the topdressing ratio was 50% ～ 60%， the biomass accumulation of total plants of the treatment was significantly higher than the normal control.With the increase of the topdressing ratio， the biomass accumulation of leaves and total plants decreased.(2)With the increase of the topdressing ratio， the nitrogen and potassium accumulation of plants decreased.(3)When the topdressing ratio was 50%， the nitrogen， phosphorus， and potassium utilization efficiency increased by 6.3， 3.4 and 25.3 percentage point， respectively， compared with the normal control.With the increase of the topdressing ratio， the nitrogen and potassium utilization efficiency decreased.(4)There were not significantly different between treatments and the normal control on yield， output value and sensory quality of tobacco leaves.When water-soluble fertilizer was applied， the topdressing ratio was about 50%， it could increase fertilizer utilization efficiency， promote root growth and biomass accumulation of plants， and yield and quality of tobacco leaves were unaffected.