The stability of bedding rock slopes with weak interlayers is influenced by the combined effects of the weak interlayers and the surrounding rock mass. Owing to the poor physical and mechanical properties of weak interlayers, these slopes are highly susceptible to bedding landslide disasters. The instability mechanisms and failure modes of bedding rock slopes controlled by faults remain a critical concern in geotechnical engineering. This study investigates a bedding rock slope located at the right bank of a large hydropower project dam site in the upper Yellow River region based on field investigations. A finite element direct solution model was developed to analyze slope stability, incorporating interface elements employed to simulate the frictional sliding, opening, and closing of structural planes. The study examines the deformation characteristics, causative mechanisms, and stability of the slope under various conditions, focusing on creep-sliding deformation and failure controlled by the F₂₇ fault. Results show that the potential sliding surface formed by bedding joints and the F₂₇ fault is the dominant factor controlling slope stability. Under natural and rainstorm conditions, the slope transitions from a state of basic stability to marginal instability. Under seismic and extreme conditions, progressive extension and expansion of bedding joints and the F₂₇ fault form a creeping bottom boundary. Tensile cracking deformation and failure occur at the trailing edge, leading to creep-tensile cracking failure along moderately to gently inclined structural planes. The slope instability poses severe threats to engineering safety, emphasizing the urgent need for targeted engineering treatments and slope reinforcement measures.