In this study, we designed and optimized the main process for CO2 cryogenic separation and purification as well as the auxiliary process of refrigeration with ammonia, both these processes are modeled using Aspen HYSYS V11. The energy‐saving potential and greenhouse gas emission reduction potential of the process flow were analyzed using the Aspen Energy Analyzer V11. The effects of the plant inlet pressure, cooling temperature, tower pressure, and number of stages on two key parameters (energy consumption per unit of product and CO2 recovery rate) were studied in detail. Simultaneously, the appropriate design parameters of the plant were obtained, and the reason for the variation law was analyzed. Finally, grey relational analysis was used to explore the correlation between the influence factors and key parameters, indicating that the number of stages has the largest impact on the CO2 recovery rate and the energy consumption per unit of product, whereas tower pressure and cooling temperature have the least impact on the CO2 recovery rate and energy consumption per unit of product, respectively.