Abstract: Based on the engineering background of No. 9303 stope in Nantun Coal mine, the mechanical mechanism of mine quake induced by the mutation of horizontal stress on the isolated island's fully mechanized caving face is studied. By simplifying hard rock in overlying strata into a mechanical model of elastic rectangular thin plates with simply supported and clamped beasms and by imposing horizontal stress caused by extraction to the clamped sides, namely the mechanical model with the elastic rectangular thin plates with simply supported and clamped beams under the action of horizontal stress, the distribution of stress and deflection of the overlying strata of hard rock is analyzed on the caving face of No. 9303 stope, and the limitation of the caving step length of the roof of the overlying strata of hard rock is studied. Based on this, the drawing pace which causes coal outburst induced by mine quake is predicted. Then the pressure is released for the predicted dangerous areas. When 2.6-level mine quake happens in the predicted areas, there is no disaster, which proves that the mine quake caused by the crack of the roof of the thick layer may be predicted.