As an important industrial by-product produced in the process of coal-fired power generation, fly ash shows great potential in CO₂ mineralization. In order to solve the problem of low efficiency of direct mineralization of CO₂ by fly ash, N-methyldiethanolamine (MDEA)/diisopropanolamine (DIPA) mixed amine solution was used to absorb CO₂ to improve the subsequent CO₂ fixation efficiency. The effects of different MDEA/DIPA ratio, solid-liquid ratio, reaction temperature and reaction time on CO₂ absorption and mineralization efficiency were systematically analyzed. The results show that the performance of MDEA/DIPA mixed amine solution is better than that of monoamine solution. When the MDEA∶DIPA is 1∶3, the solid-liquid ratio is 270 g/L, the reaction temperature is 45 ℃, and the reaction time is not less than 30 min, the CO₂ loading is the highest, which is 1.66 mol/L, and the mineralization efficiency is 45.2%. The results of FTIR, XRD and TG analysis show that MDEA/DIPA mixed amine solution mainly contained , , protonated MDEA/DIPA and carbamate. Compared with the original fly ash sample, the content of CaCO₃ in the solid product increased significantly, and mainly existed in the form of calcite. MDEA/DIPA mixed amine solution and fly ash combine CO₂ absorption and mineralization, which provides a reference for CO₂ storage and fly ash waste treatment.