Use of a dry-detoxification device for toxic gas, the device comprises an absorption tower, an ammonia adsorber, and an absorption circulating system; the absorption circulating system comprises: a circulating pump and a circulating liquid nozzle; the circulating pump is communicated with the circulating system joint via a pipeline, the ammonia gas absorption liquid inside the sump is conveyed to the circulating liquid nozzle, and the circulating liquid nozzle is mounted on the top of the tower column and sprays the ammonia gas absorption liquid downwards into the tower column characterized in that:the absorption tower comprises: a sump and a tower column communicated with the top thereof; the sump is provided with an ammonia gas inlet, a nitrogen gas inlet and an emergency inlet, wherein lines of the ammonia gas inlet and the nitrogen gas inlet lead to a position where the sump and the tower column are connected with each other, and a pipeline of the emergency inlet leads to the bottom of the sump; a liquid discharging port and a circulating system joint are arranged on the bottom of the sump, and a stainless wire filter is arranged at the circulating system joint; the sump is filled with ammonia gas absorption liquid, and a polypropylene plastic ring is arranged on the inner wall of the tower column; a pressure gauge is arranged on the top of the tower column; the ammonia adsorber is communicated with the top of the tower column, and an emergency exhaust port and an intercommunicating valve are arranged on the communication pipeline; an ammonia adsorbent is present inside the ammonia adsorber, and an outlet end of the ammonia adsorber discharges safe gas via the pipeline; the process of use of this device is as follows: 1) a set amount of nitrogen gas is introduced after ammonia gas to be discharged is passed through the absorption tower; 2) the circulating pump is opened, which drives the ammonia gas absorption liquid to pass through the circulating liquid nozzle to be further sprayed onto the ammonia gas in a downward direction, the reaction of the ammonia gas absorption liquid with the ammonia gas continues until a pressure-indicating value from the pressure gauge tends towards stability, followed by closing the circulating pump; if the pressure indicated by the pressure gauge exceeds a threshold value during this process, then the emergency exhaust port is opened and the operation is terminated; 3) a set amount of nitrogen gas is introduced for the second time and the intercommunicating valve is opened, so that a trace amount of ammonia gas is pushed by the nitrogen gas into the ammonia adsorber for reaction and then discharged via a pipeline, so as to complete a detoxification process; 4) upon completion of the detoxification process, a set amount of nitrogen gas is introduced for the third time, after which the valves are closed in reverse order from the outlet to inlet of the detoxification device, and depending on the effect of detoxification, a determination is made as to whether the absorption liquid is replaced; 5) in case of emergency, i.e. a large amount of ammonia gas needs to be detoxified, the ammonia gas is directly introduced to the bottom of the sump via the pipeline of the emergency inlet, and is then discharged through the emergency exhaust port; and under this circumstance, it is required to replace the absorption liquid after detoxification is completed. 1) a set amount of nitrogen gas is introduced after ammonia gas to be discharged is passed through the absorption tower; 2) the circulating pump is opened, which drives the ammonia gas absorption liquid to pass through the circulating liquid nozzle to be further sprayed onto the ammonia gas in a downward direction, the reaction of the ammonia gas absorption liquid with the ammonia gas continues until a pressure-indicating value from the pressure gauge tends towards stability, followed by closing the circulating pump; if the pressure indicated by the pressure gauge exceeds a threshold value during this process, then the emergency exhaust port is opened and the operation is terminated; 3) a set amount of nitrogen gas is introduced for the second time and the intercommunicating valve is opened, so that a trace amount of ammonia gas is pushed by the nitrogen gas into the ammonia adsorber for reaction and then discharged via a pipeline, so as to complete a detoxification process; 4) upon completion of the detoxification process, a set amount of nitrogen gas is introduced for the third time, after which the valves are closed in reverse order from the outlet to inlet of the detoxification device, and depending on the effect of detoxification, a determination is made as to whether the absorption liquid is replaced; 5) in case of emergency, i.e. a large amount of ammonia gas needs to be detoxified, the ammonia gas is directly introduced to the bottom of the sump via the pipeline of the emergency inlet, and is then discharged through the emergency exhaust port; and under this circumstance, it is required to replace the absorption liquid after detoxification is completed.