Abstract: Through the classification of bad geological structure and the study of ancient tectonic movement, we obtain that the area structure is the result of Yanshan movement and Himalayan movement joint action, and clarify the nature of the ancient tectonic stress field according to the structure characteristics of the mining area. We provide two methods to discriminate whether the rock mass will continue to slide along fracture surface or not, and determine the ground stress when the mining area is in a stable without tectonic movement. The direction and size of the horizontal stress and the depth of the rock mass directly influences on the subsequent development of the crack and hydraulic conductivity of rock mass. The depth should be one of the important factors of the fracture evaluation.