Abstract：Feasible drawing interval is the basis to study mining equipment of fully-mechanize coal mining with caving method. It is also a key to increase recoverable ratio of coal face and to improve quality of coal. By redeveloping the distinct element software of loose grain media，the contact relation among elements is simulated by elastic and damping elements to keep consistence with top coal drawing process. Based on Windows environment，the virtual wall is made to simulate distinctive multi-layer media. Under the condition of 0.8 m width of falling opening with lower position falling method，the falling law of top coal is simulated by distinct element method in different drawing intervals of 0.6，0.8，1.0，and 1.2 m. In the light of loss ratio of top coal and refuse rate，the drawing law and the feasible interval are studied and it is found that the scientific drawing interval is 1.0 m and the lower limit is 0.8 m. The study results of this paper are applied to determine the cut depth of coal-winning machine and the moving interval of support and conveying equipment. By using this equipment with interval of 0.8 m，the mining technology of one cut by one drawing and parallel operation is successfully applied to raise the standard of high production and effect.
