Corrosion is extremely harmful in the process of oil field production, thereby casing material selection is of great importance. When inferior casing material is selected for production, carbon dioxide corrosion may lead to casing corrosion perforation, which may affect normal production and cause safety and environmental problems in extreme cases. If high-level casing material is selected for production, it will cause economic waste. The work aims to make material selection more reasonable. A set of new ideas for casing selection was proposed based upon long-term corrosion rate of different materials calculated by De. Warrd corrosion prediction model. Well A in Bohai Offshore Oilfield was designed in this method, and design results were verified by performing laboratory experiments. The casing selection results from the experiments were consistent with those from new design method, which verified accuracy of the method. A set of methods is proposed for casing material selection in CO2 corrosion environment is proposed: corrosion rate of different materials is calculated and converted into long-term corrosion rate. Then the maximum allowable wear extent of the casing is calculated according to casing strength requirement. Finally, casing selection material is determined. This new method can effectively reduce cost of casing material selection and make for guaranteeing oilfield development efficiency while maintaining wellbore integrity and controllable well control safety.