The　simultaneous　partial　nitrification,　anammox　and　denitrification　(SNAD)　process　for　treating　mainstream　wastewater　was　investigated　under　different　intermittent　aeration　modes.　By　controlling　the　aeration　time　of　20,　60　and　180　min　during　the　intermittent　modes,　the　oxygen　concentration　remained　3.50,　1.45　and　0.70　mg.L-1.　Correspondingly,　the　reactor　achieved　the　nitrogen　removal　rate　of　0.17,　0.29　and　0.30　kg　N.m(-3).d(-1).　Meanwhile,　the　average　total　inorganic　nitrogen　(TIN)　removal　efficiency　reached　93.4%,　87.5%　and　92.7%.　The　effluent　NO3　--N　concentration　was　very　low.　High-throughput　sequencing　analysis　indicated　that　the　proportion　of　nitrite　oxidization　bacteria　(NOB),　anammox　bacteria　and　denitrification　bacteria　was　0.15%,　0.33%　and　8.78%.　Candidatus　Anammoxoglobus　was　the　abundant　anammox　bacteria　genus.　Further　study　on　the　unclassified　sequences　revealed　the　possibility　of　the　high　relative　abundance　of　Nitrosomonas-related　genus　and　Candidatus　Kuenenia-related　genus　on　the　SNAD　biofilm.