In order to solve the technical problem of residual ammonium bisulfate (ABS) in SCR fly ash in China,alkaline and acidic fly ash were selected as the test materials,and the two kinds of fly ash were added with water to remove ABS,and the effect of internal alkali/alkaline earth metals in fly ash on the removal of ABS was studied; on this basis,a certain amount of calcium-based alkali and water were added to explore the effect of this method on ammonia desorption in fly ash. The results show that adding a small amount of water to the ash and stirring at room temperature can promote the release of part of the ammonia in the alkaline ash,while the acid ash releases very little ammonia. Adding 1% Ca(OH)2,2% H2O to acid and alkaline ash,more than 95% of the ammonia in the ash is removed after stirring 5 minutes. Under the same conditions,the effect of CaO on ammonia removal in fly ash is slightly worse than Ca(OH)2. Compared with the heating method,the alkali addition method is carried out at room temperature,and little water is added,so the ash is easy to dry. The test device for ammonia removal in ash based on the alkali addition method has a good deamination effect. For fly ash containing 300×10-6 ABS,the addition of 1% Ca(OH)2 and 2% H2O can remove 75% ABS from fly ash by mixing with a mixer without heating treatment. After heating treatment,the ammonia in the ash is further removed,and the ammonia removal rate can reach more than 90%,which can ensure that that the content of ammonia in ash is less than 100 mg/kg after treatment,and will not have an adverse impact on subsequent utilization.