Abstract:  According to the geological condition of buried deep with thin bedrock coal seam in the 11011 working face of Zhao-Gu No.1 coal mine，the paper discussed the conditions of thin bedrock water gushing and running sand coal seam by using the coal mine field investigating and statistical analysis method．After analyzing and calculating the working face roof’s structure instability mode by using the theories of ‘masonry beam’ and ‘step beam’ we have analyzed the overlying strata damage，migration evolution rule of fractures．The results show that and the height of the working face roof water fracture zones is about 48 m．Therefore，some preventive suggestions and measures have to been taken into practice when mining a coal within such a range．The measures can also guide other coal mines with similar geological condition．

Key words: thin bedrock, coal seam of having water outburst, similarity simulation, evolution rule