For the cylinder gravity wharf,there is not a clear definition and mature design calculation mode yet,and it is lack of practical project and the renovation is difficult.Thus,based on Shajiao C power plant coal unloading wharf structure renovation project,we adopt the scheme of setting the reinforcement grid around the column cylinder and erecting formwork outside,using the existing cylinder based to implement the underwater casting of the high-performance concrete structure,and enlarging the cylinder diameter and self-weight to deal with the problem of the lack of overall anti-sliding and anti-overturning stability and realize the wharf’s upgrading renovation.After completion of this project,the scheme shows benefits of less impact on the normal operation and structural integrity and controllable construction progress.