Abstract: According to characteristics of 3^# coal seam firstly fully-mechanized caving face and the mechanical parameters of overlying strata in Mahuangliang Coal Mine which is in the north of Shaanxi, the paper did simulation experiment by using equivalent material in the condition of thin bedrock and thick soil covered. The research pointed that the overlying strata of 3^# seam fully-mechanized caving face in Mahuangliang did not appear fully thickness cut down, the thick soil layer sink as a whole gradually after the working face's initial pressure; on the basis of the analysis for experimental support setting load and working resistance, the paper determined the reasonable parameter of the support in fully-mechanized caving face.