Abstract: The Material Point Method (MPM) is a mesh-free simulation technique that integrates the advantages of Lagrangian and Eulerian methods, providing a novel approach for simulating large deformations of slopes subjected to rainfalls. A two-dimensional two-phase single-point MPM is employed to analyze slope responses under short-duration heavy rainfall with varying soil saturated permeability coefficients and rainfall intensities. The research findings indicate that: (1) The onset of slope instability is delayed as the intensity of short-duration heavy rainfall decreases. Concurrently, the displacement curve at the slope toe transitions from rapid steep increases to gradual increments during instability progression. (2) Primary failure modes under short-duration heavy rainfall manifest as deep and shallow overall sliding or retrogressive sliding, with the latter exhibiting greater destructive potential. Under identical rainfall intensities, slopes with lower and higher saturated permeability coefficients tend to result in shallow and deep sliding failures, respectively. (3) Decreasing soil saturated permeability coefficients progressively weakens the influence of rainfall intensity on both the magnitude and distribution patterns of pore water pressure within slopes.