Abstract: Given their lightweight and regular shapes, lattice steel bridge piers exhibit excellent aseismic performance, making them widely used in high pier bridge projects in mountainous regions. During their service lifetimes, steel bridge piers inevitably suffer from damages such as corrosion. Evaluating the hysteretic performance, failure modes, and ultimate strength of lattice steel bridge piers with end corrosion under seismic action is thusly a critical engineering concern. This study first establishes a multi-scale finite element model considering local buckling and end corrosion, and validates its effectiveness. The study explores the failure mechanisms, failure modes, and changes in the ultimate strength of steel bridge piers under the coupled action of corrosion and earthquakes. On this basis, developed is a semi-theoretical semi-empirical calculation method for the ultimate strength of lattice steel bridge piers considering the impact of corrosion damage. The results indicate that end corrosion damage intensifies stress concentration in lattice steel bridge piers, causing local buckling of steel tubes to concentrate in the corroded areas. As corrosion parameters increase, the ultimate strength of the piers decreases, with reductions exceeding 10%. The calculation method for the ultimate strength established demonstrates good predictive accuracy and can provide a reference for the aseismic design and evaluation of lattice steel bridge piers throughout their lifecycles.