Take the example of Dasuji molybdenum mine in Inner Mongolia, the analysis is made on the forms of damage and types of geological hazards in the geological environment of open pit mine on the basis of the present mining situation, the further harm to the mine geological environment by the production activities are predicted and the restoration and treatment plan of the mine geological environment is put forward. This paper mainly describes the whole process of flood control dam completion from its design to the concrete construction, as well as the technical measures such as the restoration and control of the open pit and treatment of dump and tailing pond.