In order to master the special complex thick seam coal wall rib spalling law of fully mechanized working face, based on the analysis of the fully mechanized caving stoping technology and mechanical equipment, through observation of the relationship between coal seam advancing and rib spalling depth and  rib spalling rate during periodic working face with pressure and non-periodic working face with pressure, mining face rib spalling depth and rib spalling rate distribution law were concluded, which provided a reliable scientific data to improve the stoping technology and mining face safety production.