Abstract: Carbon capture is a major "near-zero carbon" energy technology, which is of great significance to the construction of green and low-carbon city in Xiongan New Area.Adsorption method is currently one of the most promising technologies for CO₂ capture.In order to obtain stable adsorption material, the microstructure and adsorption performance of five kinds of molecular sieve were studied, molecular sieves 5A was selected as modified matrix, and the influence of alkali metal ions modification on adsorption capacity of CO₂ was explored.The results showed that molecular sieves have higher specific surface area and better CO₂ adsorption with microporous and mesoporous structures.The adsorption capacity of molecular sieves 5A was the highest, and the CO₂ adsorption was reduced due to the competition of water vapour with CO₂ on active site.Compared with K,Na, Li ions, the modification of Zn ions could increase the alkaline and pore adsorption potential, and increase the adsorption capacity of CO₂ from 9.61% to 12.02%.When the moisture content of Zn-modified 5A molecular sieve was lower than 8%,the zinc carbonate hydrate formed would produce new adsorption site, which would promote the increase of adsorption capacity with the increasing of moisture content.Moreover, the adsorption capacity of the Zn-modified 5A molecular under multiple absorption-desorption cycle reached great stability, which endowed the material with certain application potential.