NOVELTY - Separating ammonia, comprises circulating tower gas via a waste heat boiler and a gas pre-heater, recovering heat, cooling, partially separating gas containing ammonia and water mixture, cooling gaseous ammonia, gasifying liquid ammonia, passing gaseous ammonia into an ammonia product processing section, separating residual liquid of ammonia and water, performing selective absorption of ammonia, remove residual liquid absorbent from gas with ultra-low ammonia concentration, purifying the recycled gas, recycling the dissolved gas other than ammonia, desorbing the absorbent and recycling.    USE - The method is useful for separating ammonia (claimed).    ADVANTAGE - The method is energy-saving and ensures efficient separation of recycled absorbent and circulating gas.    DETAILED DESCRIPTION - Separating ammonia, comprises: (i) preparation stage: circulating tower gas via a waste heat boiler and a gas pre-heater, recovering heat, passing into a gas cooler for cooling, partially separating gas containing ammonia and water mixture, passing gas phase into a heat exchanging evaporator, cooling gaseous ammonia, gasifying liquid ammonia, passing gaseous ammonia into an ammonia product processing section, passing the gaseous phase into a gas-liquid separator after heat exchange, continuously separating residual liquid of ammonia and water and passing the residual circulating gas into a cyclic compression section of the next cycle; and (ii) production stage: passing the gas from a circulating tower into the waste heat boiler and the gas pre-heater for heat recovery, passing into the heat exchanging evaporator, heating rich liquid absorbent from a flash evaporator and recycling heat, then passing the tower gas into a gas cooler, further cooling to room temperature, passing into an absorption tower, processing gas using the absorbent, performing multi-level cooling, performing selective absorption of ammonia of the discharged tower gas, recycling the gas with ultra-low ammonia concentration into the gas-liquid separator to remove residual liquid absorbent, purifying the recycled gas and passing into a cyclic compression section of the next cycle, outflowing the rich liquid absorbent from the absorber bottom into the flash evaporator, pressurizing at one or two more stages, recycling the dissolved gas other than ammonia, passing dissolved gas into a gas recovery section, passing absorbents into the heat exchanging evaporator, heating tower gas at high temperature, desorbing the absorbent contained in ammonia gas and passing into the ammonia product processing section, passing the desorbed diluted absorbent liquor into a cooler, cooling, and pressure feeding into the absorption tower using a high pressure pump for recycling, where the absorbent is ethylene glycol, polyethylene glycol, triethylene glycol, glycerol or its derivatives and the two-stage processes are achieved by adopting two valve switching technology, where the switching valve of the preparation stage are four in number and that of the production stage is six in number and the valve is installed in the process line according to the corresponding process flow.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the process flow of ammonia separation.