In order to investigate the overall stability of I-shaped stainless steel member under axial compression load, the nonlinear finite element analysis of the stainless steel members subjected to axial compression load was performed by ANSYS software. By comparing the numerical results with the experimental results, the accuracy of the finite element model was verified. The effects of initial geometric imperfections, section residual stress, material mechanical properties, and section width-thickness ratio and slenderness ratio on the overall stability of the members were parametrically analyzed by means of the validated finite element analysis. According to the comparison, it can be seen that the material mechanical properties and slenderness ratio of the members are the key influential factors. Based on the parameter analysis, a new three-segment formula for calculating the overall stability coefficient was proposed by data fitting. The proposed three-segment formula can accurately predict the overall stability bearing capacity for I-shaped stainless steel member under axial compression load.