Abstract The present study investigated the corrosion behavior and mechanism of B10 copper tubes used for shipboard pipelines through various analytical techniques, including macroscopic inspection, chemical analysis, electrochemical impedance, corrosion product morphology, and physical phase and electron microscopic observation. The research findings revealed that the surface corrosion product film on the B10 copper tube in seawater mainly consists of Cu2O. Furthermore, the corrosion behavior under actual working conditions was attributed to crevice corrosion, non-electric coupling corrosion, and the corrosion mechanism was found to be the result of the combined effect of oxygen concentration difference cell and occlusion cell autocatalytic effect. These observations provide valuable insights into the corrosion performance of B10 copper tubes in seawater, which could potentially aid in improving their durability and reliability in marine applications.