Mohr-Coulomb model is a perfect elastoplastic model. It only considers the variation of material strength with lateral compressive stress, but doesn’t consider the variation of elastic modulus with lateral compressive stress and stress level and this is accordant with the true characteristic of geological material. The elasticity modulus in Mohr-Coulomb model was modified by employing the processing method of tangential modulus in Duncan-Chang nonlinear elastic model. In modified model, the stress-strain curve in elastic phrase behaves as hyperbola. In order to embed the modified model in FLAC3D program (Fast Lagrangian Analysis of Continua in 3 Dimensions), a preprocessing program was written and was employed to analyze numerically the bearing capacity of rigid piles loaded laterally.