The dip angle in the red bed of eastern Sichuan is generally relatively small， a special form of sliding-buckling deformation appears on the gently inclined and consequent slope. Compared to bedding-sliding， its failure、 stress and deformation are more complicated. In this paper， based on the analysis of the deformation mode of Xinglang slope， the damage process and micromechanical analysis are carried out based on PFC2D software. The results revealed that： due to the topographic features of steep at the top and slow at the bottom which affected by the wide and gentle folding in east Sichuan， the main reason why the sliding-buckling happens is the stress concentration caused by the gentle rock stratum and old landslide accumulation. The deformation damage mode is analyzed into three stages： sliding-bending bulging， strong bending-bulging and sliding-buckling. The displacement of the model damage nephogram shows that the rock body faults and shear characteristics due to stress concentration exist at the location of monitoring point 2 in the middle of the landslide， which is consistent with the actual investigation. The central buckling of the landslide shoed compressive stress concentration before sliding， when the stress concentrated to certern degree， the rock mass sheared along the bedding or the break zone， by which the deformation pattern of sliding-bending-buckling formed. The research has referrencical significance for the stability evaluation of other similar slope.