The in-plane and out-of-plane global stability of tower crane’s tapered luffing jib was analyzed,which consists of tapered and uniform segments.From the governing differential equation for buckling of a multi-step column,the formula for solving the exact Euler critical force of global stability was obtained with the transfer matrix method.The tapered column was simulated by multi-step columns,and then the non-uniform structure with tapered and uniform segments was generalized into multi-step columns for buckling analysis.The results in the present paper are compared with some classical and ANSYS results.It shows that the proposed method provides higher computation accuracy.When using the multi-step column of 6 sections with the same length to simulate the tapered column,the error of Euler critical force is less than 0.5% .