Abstract: Bank failure plays a vital role in fluvial processes and river pattern transformation in meandering rivers, driving lateral migration and increasing channel sinuosity. Field surveys on meandering rivers of the Zoige Plateau in the Yellow River source region during 2011-2016 demonstrated that the bank failure in the outer bank is the cantilever pattern in the peat-type meandering river, but the processes of this cantilever bank failure is little known so far. To analyze the cantilever bank failure, the Bank Stability and Toe Erosion Model (BSTEM) is applied to study the stability of bank and slope, and to simulate bank erosion and collapsing processes. The stability of the peat-type bank is closely related to the water content of the peat layer. If the water content increases, not only the driving force of bank failure is strengthened, but also the shearing resistance is weakened, which is unfavorable to the stability of the peat-type bank. The thickness of two-layer bank material has an important influence on the bank stability. The increasing of the peat layer thickness strengthens the bank stability, whereas the increasing of silt layer thickness reduces the stability.