Abstract: 2×600MW supercritical unit seawater cooling water pipeline of Zhuhai Jinwan Power Plant is two reinforced concrete pipes with inner diameter of 3.45m and single pipe length of 632m, connecting seawater intake pump house and steam engine house. Power plant cooling water system energy conservation operation reform needs to connect two water pipeline, to meet the requirements of 20 days to complete transformation period, designed with independent intellectual property rights of large diameter water pipe connection structure(Reconstruct concrete pipe bond, RCPB) and construction method, and through the construction of the water pressure experiment verify the safe reliability of the joint, which can be taken as reference to renovation project。