Taught is a method for removing ammonia nitrogen from an ammonia-containing solution via atomization, comprising a) adjusting the pH of the ammonia-containing solution to above 10 by adding a base; b) after mixing, atomizing the ammonia-containing solution to produce an ammonia-containing mist so as to increase the gas-liquid interface and allow ammonia to transfer from the ammonia-containing mist to an ambient gas yielding a clean mist; and c) re-aggregating said clean mist. The method is applicable for treatment of liquids containing high, medium and low ammonia nitrogen concentration.