Abstract: There is much thiamine in rare earth ore leaching wastewater,discharge without purification will cause environmental pollution.Using laboratory simulating prepared ammonia nitrogen wastewater as raw material,with conditions of pH of 7, content of Cl- was 500 mg/L,polar distance of 3 cm,20 V voltage electrolysis for 3 hous,content of ammonia nitrogen decreased from 100 mg/L 10.91 mg/L.Orthogonal test indicated that,factors affect the ammonia nitrogen removal rate decreased by voltage>［Cl-］>pH>polar distance.