To investigate the effects of different ratios of zinc(Zn)，manganese(Mn) and boron(B) elements on photosynthetic characteristics，carbon and nitrogen metabolism，and quality of cigar tobacco leaves，the variety of‘ Dexue1’ was selected as the experimental material，and the stromal pigment content，net photosynthetic rate，carbon，nitrogen metabolism enzyme activity，the chemical composition of fermented tobacco leaves and Zn，Mn and B element contents of the tobacco were analyzed.The results showed that:(1) The application of Zn，Mn and B at different ratios increased the stromal pigment content，net photosynthetic rate and the Zn，Mn and B contents of cigar tobacco leaves，improved the activities of amylase(AL)，nitrate reductase(NR)，glutamine synthetase(GS) and carbon and nitrogen metabolites，and coordinated the carbon and nitrogen metabolism of tobacco plants.(2) Compared with CK(Zn∶Mn∶B=0∶0∶0)，the content of total sugar and reducing sugar in T2 treatment(Zn∶Mn∶B=4∶4∶3) increased by 51.39% and 66.67%，respectively，the content of nicotine and total nitrogen decreased by 12.08% and 20.22%，respectively，the content of Zn，Mn，and B increased by 0.17，1.98 and 0.65 times，respectively，the ratio of potassium to chlorine and the ratio of nitrogen to alkali was better，which met the production requirements of high-quality cigar leaves. In conclusion，it could be concluded that the Zn，Mn and B ratio of the T2 treatment(Zn∶Mn∶B=4∶4∶3) and T3 treatment(Zn∶Mn∶B=2∶3∶2) was suitable for the production of cigar tobacco in Shifang city，Sichuan province，which could significantly enhance the photosynthetic characteristics，carbon and nitrogen metabolism intensity and improve the quality of cigar tobacco，and provide theoretical basis and technical guidance for the production of high-quality cigar tobacco in Shifang city，Sichuan province.