Abstract: In addition to the formation, lithology and geomorphic features in the Yangjiao landslide area, geological structures often played a key role in landslide formation. Furthermore, the massive slip of landslide was often induced by extreme external force, such as strong earthquake, heavy rainfall, etc. The study on landslide formation mechanism contributed to carry out an objective analysis and evaluation of its stability, providing a scientific basis for decision making to the project construction.