Abstract: In response to the special mining condition of the weak roof and floor in the working face of the thin seam, the difficulties and key technology of gob-side entry retaining in thin seam have been proposed. By using the theory analysis and numerical simulation, the failure characteristics and deformation law of surrounding rocks of gob-side entry retaining in thin seam have been analyzed. The structure model of gob-side entry retaining has been set up in thin seam coal mining. At the same time, Through the numerical simulation analysis and expounding the basic principle gob-side entry retaining in thin seam, it has been put forward that the optimization scheme of gob-side entry retaining was to “built waste stone wall in the goaf first, then timely build cemented filling body and long steel beams and monomer pillar support in roadway at last”. Accordingly, the gob-side entry retaining speed was improved obviously. The result of the actual measurement in Zhaoguan coal mine shows that the roof subsidence is only 197 mm; the floor heave is 83 mm；the convergence of two ribs is 327 mm, consequently, the mining efficiency reached up to 18 m/d.

Key words: soft roof and floor in thin coal seam, gob-side entry retaining, deformation and failure of surrounding rocks, filling body