Abstract: In order to investigate the bending behavior of cold-formed steel I-beams, a total of 9 cold-formed I-beams with three different sections were tested. And tests were simulated by finite element analysis. The well fitting between finite element analysis and test results proves the validity of the finite element method in this paper. Then a large number of parametric analyses were carried out through the finite element analysis on typical members and the following conclusions can be obtained: with the increase of steel strength, the decrease of beams’ length, the increase of height-to-thickness ratio of the web and width-to-thickness ratio of flanges, the members’ load-carrying capacity increases. Finally, strength-reduction method for the ultimate load-carrying capacity of cold-formed I-beam was proposed, and the ultimate load-carrying capacity from this method agrees well with the experiment results, so the strength-reduction method in this paper is valid and can be applied to practical engineering.