Abstract: Municipal solid waste incineration fly ash possess great CO₂ absorption potential because it is rich in alkaline substances. This paper explores the CO₂ absorption capacity of domestic waste incineration fly ash through simulated accelerated carbonization experiment, and studies the theoretical CO₂ absorption capacity of fly ash over the pasted years based on Steinour equation. The results show that the release and implementation of standard for pollution control on the municipal solid waste incineration (GB 18485-2014) led to the increase of the proportion of alkaline components in fly ash, which increased the absorption potential of fly ash to CO₂ by about 1.33 times; the theoretical absorption capacity of fly ash to CO₂ in 2020 was calculated to be 3.3993 million tons, and the actual absorption capacity of fly ash to CO₂ in 2020 was calculated to be 163,400 tons by accelerated carbonation experiment, which only accounted for 4.8% of the theoretical absorption capacity. This is mainly due to the wrapping of fly ash by calcium carbonate and other polymers produced in the carbonization process, which makes it difficult for external CO₂ to enter the internal fly ash; the leaching experiment shows that the leaching concentration of Zn and Cd decreases by 10%-18% and 9%-30% after accelerated carbonization. The study shows that accelerated carbonization is theoretically feasible for the synergistic disposal of fly ash, and can be one of the technical ways to achieve the goal of "double carbon" in China.