To study the effect of corrosion on the bearing capacity of compression-bending steel members, especially the local buckling behaviors, six H-shaped Q345 steel short columns with different corrosion degrees were designed. The outdoor accelerated corrosion test for up to 2 years, monotonic tensile test of standard specimens and eccentric compression test of steel columns were carried out, respectively. The volume loss ratio was used to evaluate the corrosion degree of each specimen. The relationships between failure mode, bearing capacity and deformation behavior to corrosion degree were analyzed. In addition, based on the experimental result, the interactive modeling was carried out by the software Geomagic Studio and ABAQUS, and then the deterioration laws of the bearing capacity of corroded H-section compression-bending steel members under the real corroded surface was also studied. The results showed that the bearing capacity of H-section compression-bending steel member decreased gradually with the increase of corrosion degree, and the yield load, ultimate load and buckling load of the most seriously corroded specimen PY-6 decreased by 22.8%, 23.4% and 33.3%, respectively. Corrosion changed the failure modes of the specimens and gradually decreased the half-wavelength of local buckling, which weakened the plastic deformation capability of specimens, and leaded to the transformation of steel members from strength failure to stability failure. Finally, the novel method considering the corrosion surface morphology was verified by comparing the finite element solutions to the experimental result. It was found the rough surface of the corroded specimens caused the uneven stress distribution and stress concentration. The location of maximum stress was located in the most severely corroded area, which leaded to the failure of the specimens.