In order to improve top coal recovery rate to guarantee safety of fully mechanized caving face, FALC3D numerical simulation method was used to discuss vertical stress in different advance distance of large mining height full mechanized mining caving face in a mine, overlying strata plastic zone law and stress size of working face hydraulic support, which showed that vertical peak stress was about 6m ahead of coal wall, and its range was about 23~28.1MPa. Meanwhile, mining influence scope of intense distribution was within 4~8m, and average maximum resistance of stope support was about 14 000 kN.
