• Cryogenic fractionation process is simulated and the parameters effecting system energy consumption is analyzed. • Fractionating tower pressure, condensation temperature and reboiling temperature have great impact on capture performance. • High CO 2 content in extraction gas is suitable for cryogenic fractionation. • Through literature comparison, the reliability of the cryogenic fractionation is proved. CO 2 -EOR is a recognized effective technology to enhance oil recovery by injecting CO 2 into the reservoir to increase layer pressure. With the exploitation of oil, the overflow of large amount of CO 2 has caused great difficulties to gas treatment and transportation, even affects the climate if it is discharged directly. CO 2 capture from extraction gas plays an increasingly important role in oilfield due to these problems. Compared with other methods, cryogenic fractionation is an ideal method for large extraction gas volume and high CO 2 content. In the presented work, Aspen HYSYS was used to simulate the cryogenic fractionation separation process with 100,000 Nm 3 /d extraction gas and 81.4% CO 2 content. Meanwhile, the main factors including pressure of fractionating tower, condensation temperature, reboiling temperature, and CO 2 content in raw gas which effect system cooling consumption are also analyzed. The simulation results show that the CO 2 purity and recovery can reach over 95% and 90% respectively for high CO 2 concentration. The effect of these parameters on system overall cooling consumption is significant and the reasonable parameters are obtained in this work. The results will provide some improvements for scale-up application of cryogenic fractionation in extraction gas CO 2 capture.