<p>The creep characteristics of slip soils have important influences on the stability of landslides. In this work, to investigate characteristics of creep strain-time, isochronous stress-strain, creep rate-time and creep modulus-time of the undisturbed soils of the landslide sliding zone in the Jinpingzi area, indoor shear creep tests were carried out. To study the creep deformation characteristics of the undisturbed soils of landslide sliding zones, a discrete element contact model that considers the time-weakening effect of the interparticle bond strength was established. A discrete element constitutive subroutine (DLL) was generated by using C + + so that it can be called by the particle flow program (PFC^3D). Direct shear creep tests under different normal stresses were subsequently simulated using the developed creep contact model. The contact parameters were calibrated via the test curves. The results showed that the proposed modified linear bonded contact model has good applicability to the undisturbed soils of landslide sliding zones. The evolution trends of the effective coordination number and anisotropy coefficient were explored to analyze the micromechanical mechanism of creep failure. This study provides a numerical method for analyzing the creep mechanical properties of slip soils.</p>