Novel dynamic equipment with gas in and out continuously was developed to study the capture capacity of CO 2. Municipal solid waste incineration (MSWI) fly ash has a high capture rate of CO 2 in CO 2-rich gas. Fly ash can sequester pure CO 2 rapidly, and its capacity is 16.3 g CO 2/100 g fly ash with no water added and 21.4 g CO 2/100 g fly ash with 20% water added. For simulated incineration gas containing 12% CO 2, the capture rate decreased and the capacity was 13.2 g CO 2/100 g fly ash with no water added and 18.5 g CO 2/100 g fly ash with 20% water added. After accelerated carbonation, the C and O contents increased, indicating CO 2 capture in the fly ash; CO 2 combines with Ca(OH) 2 to form CaCO 3, which increased the CaCO 3 content from 12.5 to 54.3%. The leaching of Pb markedly decreased from 24.48 to 0.111 mg/L.