CO2 flooding technology, as a mature tertiary oil recovery technique, has been widely applied in complex small fault block oilfields. However, severe gas channeling during CO2 flooding often results in an oil displacement efficiency improvement of less than 10%. To address this issue, this paper explores the method of foam profile control and plugging to effectively enhance CO2 displacement efficiency. Using the JS oilfield as a case study, this paper compares the foam performance of gas-soluble plugging agent G-CF4 with water-soluble plugging agent W-CF1. This paper also tests the plugging performance and oil displacement efficiency of the agent with better foam performance. The results show that under the target reservoir conditions, the optimal foam system is 0.25% G-CF4. Moreover, the greater the permeability gradient of the core combination, the stronger the plugging ability of G-CF4 in high permeability cores. In the 88 mD gradient core combination, the resistance factor of high permeability cores is 2.5 times that of 50 mD gradient. In the 88 mD gradient core combination, G-CF4 can maintain the resistance factor of high permeability cores above 9.2. By first injecting 0.25% G-CF4 solution at 0.3 PV, followed by CO2 flooding, the original CO2 flooding oil displacement efficiency can be improved by 15%. This study provides laboratory experimental support for the optimization of foam plugging technology in the JS oilfield.