Abstract: The dam body is an important hydraulic structure. In order to solve the contradiction between the protection of dam and mining, the feasibility of coal mining under the reservoir is demonstrated by using the mechanism of green mining and the height of water-flowing fractured zone. The determined mining sequence of working face was studied to achieve the purpose of reducing the damage to the dam and surface. The numerical simulation method was used to analyze the tensile stress of dam. By means of probabilistic integration method, the horizontal deformation of the surface of the dam is predicted and the corresponding stress cloud and deformation data are obtained. The stability of the dam is further determined through the field measurement and the reinforcement measures taken during the recovery process.