To enhance the corrosion resistance of austenitic stainless steel in molten Pb-Bi alloy eutectic, herein, hot-rolled plates of alumina-forming austinite (AFA) steels with varying Al contents (3.5%-4.5%, mass fraction) are made and pre-oxidized in air at 800 ^oC for 20 h. Then their corrosion performance was comparatively assessed in oxygen-saturated Pb-Bi alloy eutectic at 600 ^oC up to 10,000 h via static immersion test, surface and cross-sectional morphology observations, along with compositional analysis of the formed oxide scales. Results demonstrate that the corrosion resistance to molten Pb-Bi alloy eutectic of AFA steel increases with the increasing Al content, especially, the steel with 4.5%Al exhibits superior corrosion resistance with a damage area ratio less than 20% for its pre-formed Al₂O₃ scale. In fact, this phenomenon may be ascribed to that during the long-term corrosion process, due to the existence of weak local spots within the pre-formed Al₂O₃ scale, where micro-defects will be generated, at the same time, the NbC particles on the surface may be oxidized to Nb₂O₅, which can further induce microcracks in the surrounding Al₂O₃ film. These provides a rapid pathway for the inter-diffusion of alloying elements and O, leading to localized internal oxidation and causing the pre-formed Al₂O₃ scale to be damaged. The findings reveal the critical mechanisms governing long-term corrosion performance of the pre-oxidized AFA steels in molten Pb-Bi alloy eutectic cooled nuclear systems.