Abstract: According to geological conditions and coal seam occurrence conditions of Lu'an Group in Shanxi,using similar simulation test methods, the test model frame developed by Taiyuan University of Technology was used to simulate five coal seams. These coal seams were divided into two horizontal layers, coal mining is in accord with time similar ratio strictly. Using a digital camera to observe the breaking and bending of the basic roof, combining with the camera records from each level displacement of each section in the mining process and after the excavation, the paper analyzes commonality and particularity of the breaking and bending of the basic roof.