<p>Based on the effect of atmospheric environment, the mechanical properties of loess high fill slope have changed after filling, and its deformation, stability and failure mode have been affected to some extent. In this paper, the model test study of the deformation and failure modes of multi-stage loess high fill slopes under consolidation-rainfall-evaporation coupling effects is conducted. The deformation and instability characteristics, seepage characteristics, mechanical response characteristics, and failure patterns of loess high fill slopes are studied. The results show that the loess high fill slope generates cracks during the consolidation period, which are intensified and developed under the action of rainfall-evaporation cycles. Under the action of rainfall, preferential flow paths are formed, which direct the processes of slope deformation and eventual collapse. Influenced by soil consolidation, rainfall infiltration, and evaporation, the water content, matric suction, and earth pressure of loess high fill slopes fluctuate, while the displacement gradually increases. Through experiments, the instability process and failure mode of loess high fill slopes under the coupling effects of consolidation-rainfall-evaporation are revealed. These research results provide valuable reference for the stability evaluation of high fill slopes in loess areas.</p>