To reduce the energy consumption and improve the efficiency of the carbon capture system, the methyldiethanolamine (MDEA)+piperazine (PZ)⁃based carbon capture process was studied with HYSYS based on the CCUS⁃EGR pilot test of the Maokou Formation gas reservoir in the Wolonghe Gas Field, southwestern China. The optimal operating parameters were determined by sensitivity analysis and response surface methodology (RSM) as follows: mass fraction of MDEA in the lean solution at 26.6%, mass fraction of PZ in the lean solution at 10.3%, lean amine solution flow rate at 70.3 m³/h, and the lean amine solution inlet temperature at 25 ℃. Under these conditions, specific energy consumption for CO₂ removal was reduced by 8.3%, and the CO2 removal rate was increased by 17.0%, reaching 99.8%. Accordingly, an optimized carbon capture process scheme was proposed, involving primary pressurization followed by carbon capture and the addition of lean amine solution circulation. After improvement, the system energy consumption was reduced by 11.9%.