Abstract: zeolite based CO_2 adsorbents has many advantages of low energy consumption,low corrosion rate to facility and high cyclic stability,while its adsorption capacity is relatively low. In order to screen out zeolite adsorbents suitable for large-scale CO_2 capture technology,advanced synthesis methods are needed to improve the CO_2 sorption capacity of zeolite adsorbents to overcome the disadvantage of low sorption capacity. In this paper,the NaY zeolite was synthesized through hydrothermal synthesis,and the CO_2 adsorption properties of NaY,13X and 4A zeolite adsorbents were investigated. The influence of pressure,temperature and sodium bromide modification on the adsorption capacity was analyzed comprehensively. The results show that the CO_2 adsorption capacity of the three adsorbents decreases with the increase of temperature but increases with the increase of pressure. NaY zeolite has the highest CO_2 adsorption capacity at 25 ℃,0.1 MPa,which is 3.74 mmol/g. And its adsorption performance maintains stable after 8 regenerative cycles with a decrease of 2.5%. The NaY zeolite modified with sodium bromide impregnation method was investigated. The results show that the CO_2 adsorption capacity of NaY zeolite enhanced by impregnation modification with sodium bromide. With the increasing concentration of sodium bromide solution,the CO_2 adsorption capacity of the modified adsorbent increases within certain limits. The NaY zeolite modified with sodium bromide solution of 0.1 mmol/g shows the CO_2 adsorption capacity of 4.05 mmol/g at 25 ℃,under 0.1 MPa pressure,of which the performance is improved by 8.4% comparing to the unmodified sorbents. However,when the concentration of the sodium bromide solution exceeds 0.1 mmol/g,the performance of the adsorbent is not significantly improved by further increasing the concentration. The optimal concentration of the sodium bromide solution used for impregnation method is 0.1 mmol/g.