The failure scope of overlying rock was a very important index related to safety production in coal mine, , it was necessary for each mine before production to predict the extent of overlying rock damage after coal mining. In order to analyze damage scope of overlying strata after top coal caving in No. 3 coal seam. The yield ratio, split production ratio and broken ratio were simulated and analyzed by means of numerical simulation. The results showed that the range of yield ratio was 3.3~3.8 with 3.57 as average value; the range of split production ratio was 4.7~5.8 with 5.16 as average value; and the range of broken ratio was 8.0~9.4 with 8.73 as average value.