Anammox　granulation　is　an　efficient　solution　proffered　to　enrich　slow-growing　anammox　bacteria　(AnAOB),　but　the　lack　of　effective　granulation　strategies　for　low-strength　domestic　wastewater　impedes　its　application.　In　this　study,　a　novel　granulation　model　regulated　by　Epistylis　spp.　for　highly　enriched　AnAOB　was　revealed　for　the　first　time.　Notably,　anammox　granulation　was　achieved　within　65　d　of　domestic　wastewater　treatment.　The　stalks　of　Epistylis　spp.　were　found　to　act　as　the　skeleton　of　granules　and　provide　attachment　points　for　bacterial　colonization,　and　the　expanded　biomass　layer　in　turn　provided　more　area　for　the　unstalked　free-swimming　zooids.　Additionally,　Epistylis　spp.　exerted　much　less　predation　stress　on　AnAOB　than　on　nitrifying　bacteria,　and　AnAOB　tended　to　grow　in　aggregates　in　the　interior　of　granules,　thus　favoring　the　growth　and　retention　of　AnAOB.　Ultimately,　the　relative　abundance　of　AnAOB　reached　up　to　a　maximum　of　8.2%　in　granules　(doubling　time　of　9.9　d)　compared　to　1.1%　in　flocs　(doubling　time　of　23.1　d),　representing　the　most　substantial　disparity　between　granules　and　flocs.　Overall,　our　findings　advance　the　current　understanding　of　interactions　involved　in　granulation　between　protozoa　and　microbial　communities　and　offer　new　insight　into　the　specific　enrichment　of　AnAOB　under　the　novel　granulation　model.