Compared　with　the　conventional　activated　sludge,　the　experiment　was　carried　out　to　study　the　denitrification　performance　of　activated　sludge　of　Bacillus　subtilis　(hereinafter　called　Bacillus　activated　sludge)　and　the　effect　of　Bacillus　on　microbial　community　structure.　The　results　showed　that　within　a　certain　range,　the　denitrification　rate　of　two　sludge　was　positively　correlated　with　carbon-nitrogen　ratio,　the　maximum　denitrification　rate　of　the　experimental　group　could　reach　27.144mg　TN/(gMLSS·h)　with　the　carbon-nitrogen　ratio　of　10,　about　2.7　times　of　the　control　group.　The　bacterial　community　structure　of　the　two　groups　was　compared　by　Miseq　high-throughput　sequencing,　and　the　results　showed　that　the　diversity　of　bacterial　community　in　the　experimental　group　of　bacterial　phylum,　class,　order,　family　and　genus　was　better　than　that　of　the　control　group.　The　sludge　in　the　experimental　group　mainly　included　Gemmobacter,　Brachymonas,　Thermomonas,　Defluviimonas,　Longilinea,　Ornatilinea,　Aridibacter,　Exiguobacterium　and　so　on.　These　bacteria　cooperated　to　make　the　activated　sludge　with　high　efficient　denitrification　characteristics　with　sufficient　carbon　source.　©　2017,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.