Abstract: A new method to solve geometrical nonlinear problems is presented. It has being fond that the deflection represented in terms of geometrical parameters for a compressed bar is a result of superposition by an Euler’s curve for two-force member in buckling equilibrium and a diagonal line for two-force member in stable equilibrium. Corresponding with the superposition of deflections, the load case of the compressed bar is divided into an axial force with a moment and an axial force with a shear force applied to the two-force member respectively. The analytic principle and the deflection expression for compressed bars are applicable to geometrical nonlinear analysis or buckling problems. Practical applications of analytical methods show that some brief formulas can be obtained in the load case without shear forces.