Fuente: WIPO "tobacco agriculture" The invention discloses bacillus pumilus, a method for acquiring the strain, and application of the strain in orientated degradation on nitrosoamine specifically in tobacco, and belongs to the technical field of microorganism application. The bacillus pumilus 05-5402 is preserved in the Common Microorganism Center of the Chinese Microorganism Strain Preservation Administration Committee, and the preservation number is CGMCC No. 7418. The method for acquiring the strain comprises procedures of separation, screening and purification, namely, firstly separating a strain which can degrade nicotine from tobacco plant or soil, further screening by using a culture medium which takes NNK (Tobacco-Specific Nitrosamine) as a sole carbon source and nitrogen source, and finally purifying on a culture medium plate so as to obtain the bacillus pumilus. The application of the bacillus pumilus comprises procedures of fermentation, inoculation and degradation, namely, firstly culturing the strain for 48-72 hours at 25-30 DEG C so as to obtain a zymophyte agent, spraying the zymophyte agent according to a percentage of 3-5% of the weight of the tobacco in the tobacco leaf conditioning or slicing process, and keeping the degradation time of 4-7 days. Through the adoption of the strain, high-efficient orientated degradation on nitrosoamine specifically in tobacco is achieved, and the strain is good in stress resistance, simple and convenient to obtain and convenient to use, and has high popularization and application values.