Abstract: In order to realize the light and simplified topdressing of flue-cured tobacco under biochar application, the effects of biochar application rate and topdressing frequency on tobacco growth and nitrogen accumulation were studied by using the soil column leaching test combined with field experiments. The results showed that the dosage of biochar up to 10 t/ha could significantly increase the soil water content and significantly reduce the total leaching of N. The agronomic characteristics of tobacco were mainly affected by the dosage of biochar. The agronomic traits of flue-cured tobacco were mainly affected by the dosage of biochar, and the dry matter (especially leaf dry matter) and nitrogen accumulation of flue-cured tobacco were mainly affected by the number of times of fertilizer application. The dosage of biochar, the frequency of fertilizer application and the interaction between the two had significant effects on the economic traits of flue-cured tobacco, but they were mainly affected by the frequency of fertilizer application. Overall, under the condition of 10 t/ha biochar application, two times of topdressing provided a more suitable nutrient supply pattern, improved the nitrogen fertilizer utilization and economic benefits of tobacco, which can provide a reference for the development of light and simplified fertilizer chasing pattern in tobacco cultivation.