In order to explore the effects of biochar-based fertilizer on antioxidantenzyme，osmotic regulation ability and economic traits of flue-cured tobacco，‘Yunyan 116’was chosen as the research object and three treatments were setup，including conventional fertilization(T1)，biochar -based organic fertilizer(T2)and biochar -based compound fertilizer(T3). The physiological characteristics of stress resistance of leaves and roots were determined at30，60，90 and120 d after transplanting，including activities of superoxide dismutase(SOD)and peroxidase(POD)and contents ofmalondialdehyde(MDA)，soluble protein(SP)，soluble sugar(SS)and proline. Additionally，the yield，outputvalue，averageprice，and ratio of upper middle grade leaves of tobacco after curing were analyzed. The main results wereas follows.(1)Biochar -based fertilizer improved the stress resistance and osmotic adjustment ability of tobacco plants， and T2 treatment had the best effect. The activities of SOD and POD in leaves increased by 1.1%-10.6% and 2.1%-9.5%，respectively，compared with T1 treatment，and the content of MDA decreased by 16.0% -20.5%. At the same time，thecontents ofSP，SS，and proline in leaves treated with T2 and T3 increased by 1.4% to102.1%，16.0% to52.0%，and7.8% to 41.1%，respectively. The root stress resistance characteristics of different treatments were consistent with those ofleaves.(2)Biochar -based fertilizer improved the yield，output value and ratio of upper middle grade leaves of flue -curedtobacco，with the highest yield and output value in T2 treatment，which increased by 16.9% and 21.8% compared to T1treatment，respectively.(3)Through the correlation analysis of physiological and economic traits of flue -curedtobacco，it could be seen that there were varying degrees of correlation between the two types of indicators during the four measurementperiods，with the overall correlation being the closest at 120 d after transplantation. Insummary，the application of biochar -based fertilizer improved the antioxidant capacity，osmotic regulation ability，and economic traits of flue -cured tobacco， among which T2 treatment had the best effect. The research results could provide theoretical basis and technical support for the rational application of biochar-based fertilizer.