Abstract: Preparation of FeAl/Al₂O₃ tritium permeation barrier consisting of FeAl alloy transition layer and Al₂O₃ film on the layer's surface by substrate aluminization and subsequent selective oxidation is now the first choice of tritium permeation barrier technology. The Al₂O₃ film plays a key role on the service performance of FeAl/Al₂O₃ tritium permeation barrier. Surface oxidation behaviors of the FeAl alloy and coating, including selective oxidation of Al, oxidation thermodynamic and kinetic behavior and oxidation mechanism, are reviewed. Influence of substrate elements on Al₂O₃ film forming as well as its structure and the low temperature preparation technology of Al₂O₃ film on surface of the tritium permeation barrier are discribed. The future research direction of FeAl/Al₂O₃ tritium permeation barrier is proposed.