Abstract: An excellent biocontrol strain BZ3 against tobacco mosaic virus (TMV) was isolated and screened from tobacco rhizosphere soil by the dilution separation method. The strain was identified by morphological, physiological and biochemical, as well as molecular biology analyses, and its biocontrol effects on TMV were evaluated. In addition, the strain was further analyzed by whole genome sequencing and bioinformatics. The results showed that the BZ3 strain was identified as Bacillus velezensis, and the control effects of its fermentation broth on TMV in pot and field plots were 58.97% and 72.07%, respectively. Gene function prediction showed that the genome of strain BZ3 contained many gene clusters related to the synthesis of secondary metabolites with antibacterial activities, such as surfactin. This study suggested that the BZ3 strain has excellent biocontrol effects on TMV, and the antibacterial spectrum is wide. Its genome contains a large number of gene clusters related to the synthesis of antibacterial active substances, exhibiting the potential as a biocontrol agent against TMV.