Abstract: At present, geotechnical engineers comprehensively study the stability and deformation and failure mechanism of natural steeply dipping bedding rock slopes, but it is not enough for the steeply dipping bedding high slopes under excavation works. Here, the researches on the slope structure character and deformation and failure mechanism of steeply dipping bedding high slope diseases are performed based on a treatment project for a actual steeply dipping bedding high slope. First of all, the character of deformation and failure for the slope and the slope structural features about steeply dipping bedding high slope disease are summarized. And then the stability factors, deformation and failure modes, stress state of the slope and four stages modes of deformation and failure of the steeply dipping bedding high slope disease are analyzed. On this basis, the deformation and failure mechanism of the steeply dipping bedding high slope disease is proposed. The results show that the slope structure of steeply dipping bedding high slope disease determines the development of deformation and failure mechanism, meanwhile under the effect of the external trigger factors, including excavation unloading and rainfall and so on, it will result in the slope damaged by the mode of bedding slip - crushing (collapse) sheared.