During the traditional slope stability analysis，soil-rock mixed slope is always regarded as homogeneous soil slope，and rock blocks are neglected.In this paper，a piece of MATLAB code was developed to generate random rock data containing multiple group particle sizes.By using AutoCAD，the generated rock data was conversed to interactive graphics files，which can be imported into Midas for model meshing.Then，the Flac3d model was generated through a Midas_to_Flac3d interface program，and was used to analyze the stability of the soil-rock mixed slope by the method of strength reduction finite difference，which was embedded in Flac3d strength reduction finite difference.With the developed Flac3d model，the influence of some key parameters including the soil and rock interface strength on the stability of the soil-rock mixed slope was analyzed.The results show that neglecting rock blocks may lead to large difference in slope stability evaluation.The plastic zone in the heterogeneous slope is not a similar circular arc as the homogeneous slope，but under the combined effect of a variety of plastic zone propagation routes，it shows a multi-sliding phenomenon.Meanwhile，there is an obvious rounding rock effect through the process，and the sliding length compared with the equivalent homogeneous soil slope has a significant extension.Within the selected scope of the interface parameter changes，the stiffness parameters (normal stiffness and shear stiffness) have little effect on the factor of safety，but strength parameters (friction angle and cohesion) have significant influence on the slope stability.