The　collapse　of　simultaneous　partial　nitrification,　denitrification　and　anammox　(SPNDA)　system,　caused　by　the　destruction　of　partial　nitrification　(PN),　is　the　most　likely　phenomenon　to　occur.　Therefore,　recovering　the　process　quickly　and　maintaining　efficient　nitrogen　removal　is　a　valuable　topic　for　research.　In　the　anaerobic/aerobic/anoxic　operation　mode,　SPNDA　process　was　used　to　treat　domestic　sewage　in　a　sequencing　batch　biofilm　reactor.　After　the　deterioration　of　PN　effect,　with　the　addition　of　hydroxylamine,　the　activity　of　ammonia-oxidizing　bacteria　in　the　nitrobacteria　increased　(61.0–91.3　%),　whereas　the　accumulation　of　nitrite　quickly　recovered　to　90.4　%　within　5　days.　Meanwhile,　the　nitrogen　removal　efficiency　improved　(61.8–95.6　%)　and　the　effluent　TN　was　2.1　mg/L.　Furthermore,　Candidatus　Brocadia　was　enriched　(0.50–1.82　%)　in　the　system.　The　results　indicated　that　the　addition　of　hydroxylamine　was　an　effective　strategy　to　recover　and　economically　maintain　the　SPNDA　process　for　advanced　nitrogen　removal　from　domestic　sewage.　©　2022　Elsevier　Ltd