The invention discloses Bacillus altitudinis J54 and application thereof. The Bacillus altitudinis is Bacillus altitudinis J54, is preserved in the China Center for Type Culture Collection, and has apreservation number of CCTCC No. M2019667. Separation is performed on tobacco leaves, and then screening and purification are performed so as to obtain the Bacillus altitudinis J54; through processesof fermentation, inoculation and degradation, nitrosamine (TSNAs) specific in tobaccos can be degraded effectively in the process of tobacco leaf processing or pipe tobacco preparation, and the degradation rate can reach 5.2-46.6%, so that the quality of the tobacco leaves is improved; and the bacterial strain has good resistance to stress, easy acquisition, convenient use and broad market application prospects.