<p>Rockbolts are widely employed for support in coal mine roadways. However, improper open-air storage, insufficient corrosion protection, mechanical damage during transportation, and exposure to high-temperature, high-humidity environments can lead to surface corrosion before the rockbolts are grouted and anchored. The purpose of this study is to analyze the anchorage performance of pre-corroded rockbolts under pull-out load and their impact on surrounding rock stability. A theoretical model describing deformation, stress distribution, and elastic bearing capacity of pre-corroded rockbolts under pull-out loading was established and validated through numerical simulations. Within the corrosion segment, the deformation and stress distribution curves of the anchorage body exhibit pronounced nonlinearity, with distinct discontinuities at the interface. At the loaded end, both axial displacement and interfacial shear stresses increase with longer corroded segment lengths, closer proximity to the loaded end, and decreases in diameter or elastic modulus. However, the opposite trend is observed at the free end. As the length of the corroded segment increases and both the diameter and elastic modulus decrease, the axial force within the anchorage body progressively decreases. The failure modes of pre-corroded rockbolts include slip debonding at the grout-rock interface and breakage of the corroded segment. Equations for the elastic bearing capacity and the critical conditions of these failure modes were derived. The elastic load capacity of the rockbolt increases with both the diameter of the corroded segment and its distance from the loaded end.</p>