Abstract: There was a lot of water in the goaf of 3rd coal seam in Guanzhuanghe mining area, for this issue, we measured the height of the fissure zone with methods of drilling lavage fluid leakage and fissure zone height viewer. The measure result showed that the height of the fissure zone was 44.1 m, and it was 16.3 times of the height of 11th seam. It also tested this result through numerical simulation method. The fissure zone could not get the goaf of 3rd coal seam, so the 11th coal seam can be mined without drain the water in 3rd coal seam goaf.