<p>This study aims to develop a classification framework for flexural toppling evolution that includes the division of evolution stages and the classification and identification of characteristics and potential failure mechanisms at each stage. Sixteen base friction tests were performed, varying slope angles, slope heights, bedding inclinations, layer thicknesses, and rock strengths. The evolution process was analyzed from the perspective of the development of the failure plane, in combination with qualitative and quantitative evaluations of the influencing factors. Based on these observations, the initial appearance and final completion of the primary deep failure plane are proposed as key criteria for dividing the evolution stages. Subsequently, evolution processes and their associated potential failure mechanisms at various stages were classified and identified, with a particular emphasis on the previously understudied evolution following primary deep failure plane formation. These findings collectively form the proposed classification framework. This framework refines three progressive failure modes for the primary deep failure plane, proposes two modes for the subsequent shallow failure plane, and identifies the failure mechanisms at various stages. Tensile failure is predominant during the formation of both deep and shallow failure planes, whereas shear failure along shallow failure planes eventually predominates in most cases. A sensitivity analysis revealed that compared with strength parameters, geometric parameters have greater effects on the evolution process, and an increase in slope angle or bedding inclination or a decrease in material strength accelerates toppling evolution. These findings provide an empirical basis for landslide prevention and mitigation in anaclinal slopes.</p>