In response to the frequent disturbance of the dynamic pressure of the regenerated roof and the technical problems of controlling the stability of the roadway in the process of forming a large cross-section support withdrawal channel during the expansion of the layered fully mechanized caving working face under layered mining, taking the 1200-2 fully mechanized caving working face of Baiyinhua No.4 Mine as the engineering background,analyzed the load characteristics of the overlying rock structure and the top plate of the retractable passage after the expansion of the lower layered fully mechanized top coal caving face, and studied the combined support scheme of anchor rod, metal mesh, steel ladder belt, I-steel inserted beam, suspension beam, anchor cable, and single pillar, forming a safe and efficient construction support technology system,Practice has shown that this plan can effectively reduce the subsidence of the roof, narrow the range of plastic failure zone, ensure the stability of the surrounding rock of the tunnel during the support withdrawal period, and successfully complete the efficient withdrawal of the hydraulic support. The research results can provide good reference for roof management and the smooth production of coal resources after slope expansion under similar conditions.