Abstract: Based on a great deal of field investigation, bore drilling and physical exploration, formation mechanism of Dahuaqiao slope is analyzed and a geo-mechanical mode is proposed to explore the slope deformation. The results indicate that the slope body is originated from collapse deposit which is caused by deferential settlement. The formation of Dahuaqiao slope is divided into two stages: the formation of deposit, and formation of slope body. Now weak slide surface the slope does not go through the whole slope body, and the slope is in good stability condition.