A　novel　strategy　based　on　quorum　sense　(QS)　was　proposed　to　improve　the　treatment　performance　of　the　partial　denitrification/Anammox　(PD/A)　process　at　high　loads　by　adding　immobilized　Pseudomonas　sp.　HFQ8C/N,　which　could　release　high　concentrations　of　N-butyryl-DL-homoserine　lactone　(C4-HSL),　N-octanoyl-DL-　homoserine　lactone　(C8-HSL)　and　N-decanoyl-DL-homoserine　lactone　(C10-HSL).　The　results　showed　that　adding　immobilized　HFQ8C/　N　improved　the　sludge　activity　and　settleability,　contributing　to　higher　nitrogen　removal　efficiency　at　the　high　nitrogen　loading　rate　(NLR).　It　was　proved　that　C4-HSL　promoted　the　abundances　of　Thauera　and　Candidatus　Kuenenia　at　NLR　1.68-2.52　kg　N/(m(3).d),　while　C10-HSL　promoted　the　abundance　of　Candidatus　Brocadia.　Besides,　C8-HSL　and　C10-HSL　played　different　regulation　roles　in　the　production　of　protein　(PN)　in　tightly　bound　extracellular　polymeric　substances　(TB-EPS)　at　different　loads,　improving　the　sludge　settleability.　This　study　provided　a　new　way　to　improve　the　treatment　performance　of　high-load　PD/A　processes.