Removing CO2 from CH4/CO2 mixture gas is significantly important in natural gas upgrading and greenhouse gas emission control. In order to improve the separation effect, the influence of swing on removing CO2 from offshore natural gas by the adsorption was studied systematically by experiment and simulation. Firstly, the adsorption experiment was carried out under the quiescent condition, single direction swing with a frequency of 0.12 Hz, bidirectional coupling swing with a frequency of 0.12 Hz and quiescent condition with a tilting angle of 20° by the swing experiment platform. The results indicated that the swing of the adsorber can reduce the adsorption purification effect, and which is not caused by the decrease of the adsorbent performance. Then, the adsorption purification model was established and the validity of the model was verified by experiments. Finally, the effects of tilting angle and L/D ratio of the porous zone, inlet flow rate of the mixture gas, particle diameter of adsorbent, and gas inlet distribution of the adsorber on adsorption purification under the quiescent and swing conditions were studied in detail. The results showed that decreasing the tilting angle of the porous zone and inlet flow rate of the mixture gas, or increasing the L/D ratio of the porous zone, the particle diameter of the adsorbent and the inlet amounts of the adsorber can reduce the adverse effect of swing on purification of natural gas. It is of great significance to improve the effect of adsorption purification of natural gas under swing condition by changing the adsorption conditions and structure of the adsorber. The research will provide a certain guidance for removing CO2 from offshore natural gas by adsorption.