Aflatoxin B1 (AFB1) is highly toxic and carcinogenic, which seriously endangers human and animal health. The aflatoxin degradation strains were screened from the soil through enrichment culture, initial screening and rescreening, and the efficient degradation strain was identified and the degradation characteristics were studied. The results showed that the selected strains could degrade AFB1, and the strain A12 was the most efficient one, which was identified as bacillus subtilis, named as Bacillus subtilis subsp. Inaquosorum A12, by morphological, physiological and biochemical analyses and the evolution of 16S rRNA gene system. The degradation rate of supernatant, bacterial suspension, and intracellular fluid of A12 were 87.6%, 17.3% and 10.8% AFB1, respectively. The results indicated that degradation activity of strain A12 was located in extracellular fluid, and the optimal reaction temperature and pH value for degradation of AFB1 by supernatant were 37 ℃ and 7.0, respectively. The AFB1 content could be significantly reduced by inoculating strain A12 to peanut sample contaminated by AFB1. This study laid a foundation for the biological detoxification of AFB1 by strain A12.