Abstract: The 17 Steel Code comprehensively accounts for initial defects through equivalent initial deflection，references experimental data， employs computational fitting，and determines the column curve by calculating the buckling behavior of axially compressed members under compression-bending. The column curve specified in the American Steel Code consists of two distinct phases：during the elastic stage，it uses the Euler critical force as a reference with a reduction factor of 0. 877 to account for geometric defects；in the inelastic stage，it incorporates the nonlinear characteristics of the generalized Euler's formula when materials approach their proportional limit.