Problems related to corrosion and scale precipitation caused by long-term coupling effect of ultra-high CO2 partial pressure, carbon source impurities, high salinity formation water, microorganisms and stress, and so forth, fails wellbore and string of CO2 flooding and sequestration systems, leading to high leakage risk of CO2. Commonly used anti-corrosion measurements include corrosion-resistant pipes, sacrificial anodes, coating, chemicals, of which corrosion-scale inhibitor is the most economical and effective measurement. In this paper, the main molecule structure of integrated corrosion-scale inhibitor was obtained by grafting scale inhibition group with corrosion inhibition group, and the integrated agent was obtained by compounding technology. Multiple laboratory evaluation tests including weightlessness hanging, electrochemical test and inductively coupled plasma mass spectrometry demonstrate that the integrated agent displays superior corrosion and scale inhibition performance. Field tests show that the application of the integrated agent can effectively inhibit the corrosion and scaling of the pipe string under CO2 flooding conditions and is conducive to the smooth implementation of CO2 flooding and sequestration, indicating the treatments were successfully and effectively conducted.