The invention relates to an 
ammonia nitrogen removal agent and a method for treating 
sewage by utilizing the agent, relates to the field of 
sewage treatment, and provides the 
ammonia nitrogen removalagent capable of improving a denitrifier propagation ability and with high 
shock resistance, and a method for treating the 
sewage by utilizing the agent. The 
ammonia nitrogen removal agent is preparedfrom the following components: 8 to 10 parts of 
arthrobacter globiformils, 15 to 20 parts of 
paracoccus denitrification, 10 to 12 parts of 
bacillus subtilis, 8 to 10 parts of 
nocardia amarae, 15 to 20 parts of 
nitrobacter winogradsky, 20 to 25 parts of pseudomonadaceae K50, 20 to 25 parts of pseudomonadaceae TR2, and 2 to 5 parts of 
snail stoste. The appropriate cultures are matched reasonably, so that a 
nitration-
denitrification effect achieves the best; the 
snail slime is added into the agent, so that the cultures are promoted to grow and propagate, an 
ammonia nitrogen treatment effect is improved, and the 
shock resistance is improved; 
coconut oil fatty acid diethanol 
amide converts 
ammonium at an 
ion state into free ammonia, so that a 
denitrification progress of whole denitrification culture is accelerated; in addition, only N2 is produced during a 
denitrification process, and the production of N2O products in a 
sewage treatment system is reduced, so that the environment is protected.