This paper studies the influence of corrosion on the bearing capacity of cold-formed thin-walled C-shaped steel short columns under axial compression. Through the monotonic tensile test of the plate，the mechanical property degradation law of the corroded cold-formed thin-walled steel plate was studied. Five corroded cold-formed thin-walled columns were subjected to axial compression test. Failure mode，deformation characteristics and bearing capacity of the columns were analyzed. The calculation method of the ultimate load was discussed. The experimental results show that the yield platform of corroded steel becomes shorter or even disappears，and its yield strength decreases linearly with the increase of corrosion rates. The failure mode of the corroded C-shaped short column under axial compression is local buckling failure of the web，but local buckling occurs mostly at the weakest part of the web. The ultimate load decreases linearly with the increase of the average thickness loss rate. The effective width method and the direct strength method，considering the degradation of the mechanical properties of the corroded steel and thickness reduction，can predict the ultimate load of the C-shaped steel short columns under axial compression. However，the modified direct strength method is closer to the test results，and the modified effective width method is more conservative.