A　pilot-scale　study　on　shortcut　biological　nitrogen　removal　from　synthetic　ammonia　industrial　wastewater　was　researched　in　an　aerobic-anoxic　system.　The　industrial　wastewater　contained　a　high　NH4+-N　concentration　with　80-110　mg/L.　Experimental　results　showed　that　a　stable　short-cut　nitrification　and　denitrification　was　achived　after　a　period　of　90　d　operation.　The　accumulation　nitrite　was　keeping　above　80%.　The　removal　efficiencies　of　COD,　NH4+-N　and　TN　was　95%,　99%　and　80%,　respectively.　In　addition,　the　mechanism　analysis　showed　that　the　main　reason　for　getting　the　stable　short-cut　nitrification　and　denitrification　in　the　pilot　system　was　attributed　to　the　collaboration　of　low　dissolved　oxygen　(DO),　high　free　ammonia　(FA)　and　appropriate　hydraulic　retention　time　(HRT).