Bacillus subtilis is a non-toxic and non-residual green feed additives.Research shows that Bacillus subtilis can be used for biological control or production of microbial fungicides to replace toxic chemicals.The use of UV-mutagenesis in Bacillus subtilis can achieve almost 100% death rate during experiment when treating 150 s.The mutagenic effect is the best when treating 120 s and the antibacterial effect against E.coli is most obvious.