Abstract: Abstract: According to the coal seam condations and the overlying strata mechanical properties of Longwanggou coal mine, For researching the impact of working resistance at the process of caving the extra 6 thick seam face under the condition of overlying 6 seam with close distance had been caved, the physical simulation experiment was carried out. Studies suggest that the extra thick seam of fully mechanized caving face which under the mining goaf with close distance in the mining process, the strong pressure occurred at high frequencies, the working resistance over simulate bracket range to above 24000kN and up to 82952kN when each cycles occurred after second periodic weighting; the working face, the upper bracket coal and coal wall were damaged hardly;Stent overload and pressed frame occured frequently, which seriously affected the normal production of the face, so the research suggest it is not available that caving a full thickness 6 seam of 21 m under mining goaf after caving mining method in overlying 6 seam.

Key words: Key words: seam with close distance, under mining goaf, extra thick coal seam, strong pressure, working resistance