Abstract: The bridge pile foundation in high-steep rock slopes has double functions that will not only bear the load from the superstructure,but also counteract the landslide-thrust from the pile foundation side.The bearing mechanism of piles in high-steep rock slopes is much more complex than that of piles in the flat because of the steep rock slope.Based on the bending differential equation of pile foundation under vertical load piles,the similarity rule of the bridge pile foundation in steep slopes is deduced and model tests are implemented on the basis of the similarity rule.The moment and horizontal displacements are achieved through different combined loads and load methods,the working mechanism of the pile foundation is discussed,and the distribution and influence zone of soil thrust and resistance is acquired by model tests.It will help to deeply understand the load transfer mechanism.