An　application　challenge　of　anaerobic　ammonia　oxidation　(anammox)　is　the　slow　proliferation　rate　of　anaerobic　ammonium　oxidation　bacteria　(AnAOB).　This　study　adopted　negative　pressure　coupled　with　the　direct-current　electric　field　(NP-DCEF)　to　evaluate　system　nitrogen　removal　performance.　Results　showed　that　the　total　nitrogen　removal　rate　(TNRR)　of　the　NP-DCEF　system　was　stable　at　88.6%　after　seven　days.　Compared　with　that　of　the　ordinary　operating　system　(45.4%),　the　relative　abundance　of　Candidatus-kuenenia　considerably　increased　from　51.9%　to　57.6%.　Under　transient　and　long-term　influent　fluctuation,　the　NP-DCEF　system　showed　high　nitrogen　removal　performance.　The　specific　activity　of　AnAOB　(SAA)　reached　11.0　mg　N.g　Vss(-1)　h(-1)　under　load　fluctuation,　and　it　was　8.7　mg　N.g　Vss(-1)　h(-1)　under　ordinary　operational　conditions.　In　addition,　the　specific　activities　of　hydrazine　dehydrogenase　(HDH)　and　hydrazine　synthetase　(HZS)　reached　32.66　and　92.95　U.L-1,　which　are　considerably　higher　than　those　under　the　ordinary　operating　conditions　(18.41　and　63.20　U.L-1).　These　results　indicated　that　the　novel　operation　strategy　has　specific　feasibility　and　potential　for　the　start-up　and　long-term　operation　of　anammox.