Under the guidance of the “dual carbon” strategy, CCUS technology has been widely applied in the field of oil and gas development. CCUS-EOR has also been widely applied in the field of oil and gas production, but this has resulted in severe CO2 corrosion of wellbore columns, posing a significant challenge to wellbore integrity and safety reliability.This article introduces imidazoline groups and modified n-SiO2 into the ring opening reaction of PSI through molecular structure design, achieving the coexistence of inorganic nanoparticles and organic polymer segments, and synthesizing a pre corrosion resistant working fluid(n-SiO2@PASP)It can effectively suppress the corrosion problem of wellbore tubing during CO2 flooding injection and production process.The indoor test results showed that the working fluid belongs to a mixed type corrosion inhibitor that mainly inhibits the anode, and its mechanism of action is a “negative catalytic effect” type. It has a blocking effect on the anodic reaction during the corrosion process, and the higher the dosage concentration, the higher the coverage of corrosion inhibitor molecules and the higher the corrosion inhibition efficiency. This working fluid has excellent corrosion inhibition performance in environments with large temperature differences of −25 °C −95 °C and high flow rate of 2.5 m/s CO2. The effective action time is greater than 30 days, and the average corrosion inhibition rate is 91.17% and the pitting corrosion inhibition rate is 86.96% under simulated CO2 displacement conditions. The corrosion inhibition effect is significant.