Abstract: The hard and thick roof is the force source layer of the large mining height working face. During the life cycle of different large mining height working face, the boundary conditions of the roof are different, which leads to the breaking pattern of the roof changing, and further triggers the difference in the manifestation of the ground pressure at the large mining height working faces. Therefore, analyzing the breaking mechanism of hard and thick roof during the life cycle of large mining height working faces at different spatial locations is the basis for research on the prevention and control of ground pressure. This paper takes the deeply buried large mining height working face of Huangling No.2 Mine as the background, adopts the means of geological investigation, theoretical analysis and on-site monitoring, and analyzes the breaking mechanism of the hard and thick roof through the principle of virtual work based on the boundary conditions of the hard and thick roof of a single and adjacent working face in the life cycle. The paper also analyzes the destabilization mechanism of the 21422 adjacent working face by taking the three-dimensional spatial axis rotation model of the hard and thick roof on the hollow side as an example. The research results show that, ①there are two types of roof breakage articulation in the life cycle of 21421 and 21422 working face respectively. The 21422 working face is the successive working face, with the articulation boundaries of the roof on the airside being simply supported, so the roof has asymmetric breakage. The breaking limit condition and analytical equation of each roof type is derived through the principle of virtual work. It is concluded that the pressure step of 21422 working face is smaller than that of 21421 working face, and the horizontal breaking distance of the broken block along the two sides of working face tendency is 108.41 m and 191.59 m respectively. ② It can be concluded that the breaking process of the roof is in a slewing motion through modeling the articulation of the hard and thick roof on the tendency side of the 21422 working face. According to the stability coefficient (ξ), the roof plate of the working face tends to be unstable on the proximity side, which is more likely to trigger the occurrence of ground pressure in the working face.③ Characteristics of pressure distribution one natural month after full mining of each working face verified the symmetric breaking and asymmetric breaking of hard and thick roof in 21421 and 21422 working faces. The intensity of incoming pressure and the intensity of step distance of 21422 working face are larger than that of 21421 working face.