The application of M⁃MOF⁃74 series in CO ₂ removal of natural gas was studied. The skeleton model of M⁃MOF⁃74 was established. The adsorption of pure CO ₂ gas and CO ₂/CH ₄ mixed gas in M⁃MOF⁃74 series adsorbent was calculated by GCMC method. The results showed that the order of adsorption of CO ₂ by M⁃MOF⁃74 adsorbent was Mg⁃MOF⁃74 > Ni⁃MOF⁃74 > Co⁃MOF⁃74 > Fe⁃MOF⁃74 > Cr⁃MOF⁃74 > Mn⁃MOF⁃74.When adsorbing mixed gases, the adsorption amount of CO ₂ by each adsorbent is consistent with that of pure CO2 adsorption, and the adsorption amount of CH ₄ is: Mg⁃MOF⁃74>Ni⁃MOF⁃74≈Co⁃MOF⁃74≈Fe⁃MOF⁃74≈Cr⁃MOF⁃74≈Mn⁃MOF⁃74. The law of isosteric heat of gas on M⁃MOF⁃74 is the same as that of adsorption capacity, indicating that the interaction between gas and M⁃MOF⁃74 is the main factor affecting the adsorption amount. The selectivity of each adsorbent to mixed gas: Ni⁃MOF⁃74>Co⁃MOF⁃74>Fe⁃MOF⁃74>Mn⁃MOF⁃74>Cr⁃MOF⁃74>Mg⁃MOF⁃74. Comprehensive comparison of CO ₂ adsorption capacity, regeneration energy consumption, selectivity coefficient and other parameters, Ni⁃MOF⁃74 is more suitable for the adsorption and separation of CO ₂ in natural gas.