The natural balance conditions will be disturbed and produce a series of problems when mineral deposit has mined. This paper has researched the engineering rock masses have been researched in this study, structural planes, the distribution characteristics of tectonic geological factors and the stability of engineering structures according to the theory and research methods of rock mechanics, it will provide the engineering geological evidence for mining area exploited, meanwhile pledge the safety production. Shanmen silver deposit is a large epithermal deposit,it is controlled by NE to NNE strike faults. The stability of rock mass is acted on the tectonic movement and hot metalliferous brine in long-term. Especially,strength of rock mass becomes softened, muddy and loosed under the action of water,so the lower stability of rock mass is,the easier it can take place for harm of disaster threatening production safe of mining. For this reason,it is very important that drawing up a plan to lower harm for mine and protect.