To resolve the deficiencies of the calculation model for anti-sliding pile with prestressed anchor cable, an improved model is presented with detailed derivations based on the finite difference theory. According to the actual construction process and loading conditions of pile and anchor cable, the model includes two stages, i.e. applying prestress and landslide thrusting. By improving the distribution of landslide thrust and revising the pile-anchor deformation compatibility equation, the actual active mechanical characteristics of anti-sliding pile with prestressed anchoring cable are properly taken into account. The proposed procedure is implemented into a Matlab code and used to analyze practical examples. The results are compared with those of the conventional theories. It is shown that the influence of prestress application on anchor-pile can be properly taken into account in the proposed procedure and its corresponding code, and it is not necessary to equate the anchor cable tension with the shear force and the bending moment at the top of pile. In addition, it can also be used in the design calculation for the cases that the sliding body with arbitrary thickness above the sliding surface exists in front of the piles and for the arbitrary complex foundations. Compared to the conventional theories, the improved procedure is more reasonable and reliable.