Abstract: In response to the greenhouse effect caused by excessive CO2 emissions, the development of high-performance CO2 adsorption materials is urgently needed. MOF-74 exhibits superior CO2 adsorption potential due to its tunable pore channels and excellent specific surface area. Its open pore structure allows CO2 to rapidly diffuse to adsorption sites for spontaneous capture. However, current research on the influence mechanism of different metal ratios on the CO2 adsorption performance of MOF-74 materials is still insufficient, especially the micro-adsorption mechanism remains unclear. Therefore, solventothermal synthesis was used to construct MOF-74 materials with Mg, Zn, and Ni as metal centers. SEM, BET, XRD, TG and other techniques were employed to characterize the phase structure and thermal stability of the three single-metal MOF-74 materials. The CO2 adsorption performance was analyzed using a fixed-bed reactor. The two materials with the best thermal stability and adsorption performance were selected, and their metal ions were synthesized into bimetallic MOF-74 materials at molar ratios of 1:3, 1:1, and 3:1 to analyze the adsorption mechanism for improving adsorption performance. Experimental results show that by comparing the test patterns of samples with standard reference data, the characteristic peaks and peak shapes highly match, confirming the successful synthesis of target materials. The replacement of metal central ions affects thermal stability. Zn-MOF-74 has the best thermal stability, being completely decomposed after 700°C, benefiting from the relatively higher bond energy of Zn-O and the more coordination numbers of Zn2? in the MOF-74 structure, which is not easily dissociated by thermal vibration. The Lewis acid-base interaction between Mg2+ and oxygen atoms in CO2 is the strongest, and the electrostatic interaction between CO2 and Mg2+ is more significant, making the adsorption capacity of Mg-MOF-74 reach 2.2 mmol/g with the best adsorption performance. Zn2+ and Mg2+ were selected to prepare ZnMg-MOF-74 materials at three metal molar ratios, all showing higher CO2 adsorption capacities than the three single-metal MOF-74. The optimal ratio of Zn2+ to Mg2+ is 1:3, with the maximum CO2 adsorption capacity of 3.01 mmol/g, increasing by 37% compared to Mg-MOF-74. This provides new ideas for the improvement of metal-organic framework materials and CO2 capture.