The invention discloses a method for jointly removing carbon dioxide and sulfur dioxide from smoke, which is mainly characterized in that: alkali carbonate is supported on a carrier to serve as a solid absorbent; under the condition of low temperature (60-100DEG C), CO2 and SO2 are jointly removed by utilizing vapor in the smoke in a smoke absorption reactor to generate bicarbonate and sulphite of alkali metals; the absorbent after the reaction is subjected to temperature rise (the temperature is raised to between 150 and 300 DEG C), the sulphite is not decomposed, and the bicarbonate is decomposed to generate carbonate, CO2 and vapor; after the carbonate, the CO2 and the vapor are condensed, high-purity CO2 can be separated out; the generated carbonate serves as the absorbent for recycling, and the SO2 is fixed in the solid absorbent and is discharged along with disabled materials after multiple circulation; and the smoke absorption reactor and an absorbent regeneration reactor can adopt various operating modes such as a fixed bed, a babble fluidization bed, a circulating bed and a transport bed. The method has the advantages of high efficiency of removing CO2/SO2, and simple equipment, and is an optimized scheme with low investment and energy consumption.