Abstract: Study was carried out in this paper on the overlying strata movement and strata behavior laws in the fully mechanized face in the thick coal seam with large angle by taking the fully mechanized face in B8 coal seam of Nanshan Mine as the research object and using the method of the similar materail simulation test and the field observation. The results showed that a "厂" shape mobile arch structure might be formed in the main roof and it would gradually extend to the overlying strata and then up to the surface with the mining of the coal seam; the periodic weighting showed a long weighting period and large weighting step in the middle and lower parts of the working face and a short weighting period and small weighting step in the upper part of the working face, the first weighting step of the working face was about 40.0 m, the periodic weighting step was 8.3 m to 20.7 m, the height of the caving zone was 41.0 m, the height of the fracture zone was 69.0 m and the height of the subsidence zone was 46.0 m.