Abstract: This paper takes the slope with soluble rocks and soft base as an example which lies in the south of the south abutment of the great Renyi River Bridge and analyzes the slope' s destruction types and its deforma-tion and destruction mechanism. It saggescs that the slope was destroyed by falling and there are three kinds of slope falling failure modes which are toppling(extroversion type),toppling-sliding(introversion type) and base toppling-sliding type and there are three kinds of deformation mechanism resulting in the different slope falling failure modes which are bending-fracturing ,bending-interlayer sliding and fracturing-sliding. This will be helpful to solve the engineering problem of the special slope.