The　suppressive　influence　of　salinity　on　biological　wastewater　treatment　processes　is　well　acknowledged;　nevertheless,　its　ramifications　on　emerging　Partial　Denitrification/Anammox　(PD/A)　processes　have　received　comparatively　less　attention.　This　research　endeavors　to　address　this　disparity　by　examining　the　effects　of　saline　exposure　on　the　freshwater　PD/A　process.　The　findings　revealed　freshwater　PD/A　process　can　adapt　to　salt　exposure,　initially　experiencing　reduced　nitrogen　removal　performance,　followed　by　a　gradual　recovery　to　the　initial　level.　Shorter　resilience　times　at　5　g/L　salt　compared　to　10　g/L　suggest　a　higher　tolerance　of　the　PD/A　system　to　low-salt　conditions.　Additionally,　anammox　functional　bacteria　exhibits　greater　sensitivity　to　salinity　stress　compared　to　denitrification　bacteria,　potentially　leading　to　reduced　proportions　of　anammox　(from　94.2　%　on　day　70　to　60.9　%　on　day　77)　in　overall　nitrogen　removal　during　the　recovery　phase.　Increased　secretion　of　extracellular　polymeric　substances　(EPS),　particularly　proteinaceous　substances　like　tyrosine　and　tryptophan,　is　believed　to　confer　resistance　to　salinity　stress.　Microbial　analysis　revealed　substantial　alterations　in　bacterial　community　structures　within　the　PD/A　system　in　response　to　salinity　stress,　with　notable　increases　of　PD　functional　microorganism　(e.g.,　Thauera)　and　anammox　bacteria　(Candidatus　Brocadia).　Furthermore,　relevant　functional　genes　associated　with　anammox　and　denitrification　processes　showed　increased　expression　levels,　indicating　the　survival　of　functional　bacteria.　This　likely　contributed　to　the　high　EPS　secretion　and　energy　production,　as　evidenced　by　the　heightened　expression　of　genes　associated　with　oxidative　phosphorylation　and　the　tricarboxylic　acid　(TCA)　cycle.　Overall,　this　study　provides　valuable　insights　into　how　the　PD/A　process　adapts　to　salt　exposure　by　modulating　gene　expression,　regulating　nitrogen　and　energy　metabolism.　These　findings　could　help　manage　the　influence　of　salinity　on　PD/A　process　operation,　ensuring　efficient　nitrogen　removal　in　salt-containing　wastewater　treatment　systems.