The　EGSB　(Expanded　Granular　Sludge　Bed)　reactor　was　started　up　completely　autotrophic　nitrogen　removal　over　nitrite　(CANON)　process　by　changing　the　aeration　mode　and　optimizing　aeration/non-aeration　conditions　to　ensure　the　stable　running　of　the　process.　A　study　on　different　aeration/non-aeration　conditions　of　change　about　nitrogen　removal　performance　of　CANON　process.　The　functional　bacteria　activity　in　different　sludge　particle　sizes　under　this　system.　The　different　particle　sizes　microbial　influenced　mechanism　and　the　microflora　community　structure　characteristics　in　CANON　technology　running　process　under　the　different　operating　conditions　and　system　of　EGSB　reactor.　The　constant　aeration　rates　reached　0.5L/min,　the　ratio　of　aeration/non-aeration　was　2:1　(60min:30min)　which　were　realized　that　the　purpose　of　AerAOB　(Aerobic　Ammonia-Oxidizing　Bacteria)　and　AnAOB　(Anaerobic　Ammonium-Oxidation　Bacteria)　synergistic　denitrification　and　the　activity　of　Nitrite-Oxidizing　Bacteria　was　successful　inhibition　from　3.41　to　0.75mgN/(h•gVSS).　The　results　of　bisubstrate　AnAOB　(NH4+-N　and　NO2--N)　inhibition　kinetics　fitting　by　Haldane　showed　that　the　half-saturation　constants　(ks)　and　the　inhibition　kinetics　constants　(kh)　were　106.8　and　331.90mg/L,　272.4　and　66.61mg/L　with　correlation　coefficients　(R2)　of　0.98133　and　0.99142,　respectively.　In　the　formation　of　CANON　sludge　granulation,　the　sludge　particle　size　in　the　range　of　0.154~0.335mm　was　based　primarily　on　AerAOB,　and　the　particle　size　greater　than　1mm　was　based　mainly　on　AnAOB.　The　synergy　effect　of　microbial　aggregates　and　steady　community　structure　under　the　different　particle　sizes　achieved　the　stable　running　of　CANON　technology.　©　2021,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.