Abstract: The engineering geological conditions are complicated in the very weak cemented formation of Chagannaoer No.1 Mine. The surrounding rocks in the roadway came out serious deformation and failure. Based on the basic experimental rock mechanics, we analyze the surrounding rocks' mineral composition, micro-structure and physical and mechanical properties. Combined with the deformation and failure characteristics of the surrounding rocks in the roadway, we reveal the internal and external causes of the surrounding rocks deformation and failure in a very weak cemented formation. Through FLAC^3D numerical simulation, we explore the law of influence on roadway failure characteristics. The numerical simulation indicates that the stability is relatively good through selecting the roadway close to the surface shape. To master the influence of the lateral pressure coefficient and roadway buried depth on the stability of roadway timely, this method can effectively reduce the deformation of surrounding rocks in roadway.