Abstract: In order to study the height of water flowing fractured zone above goaf, test the effect of computer simulation in analyzing the water flowing fractured zone in coal, taking the 1202（1） working face of Guyao Coal Mine as the research background, through field investigation, theoretical analysis and calculation, FLAC^3D numerical simulation and field drilling test, it concludes the height of water flowing fractured zone of 1202（1） working face: using the“upper four-zone”theory, it is concluded that the height of water flowing fractured zone is 60 m and the error with the actual field measurement of 62.18 m is only 3.51%; using FLAC^3D numerical simulation, it is concluded that the height of water flowing fractured zone is 58 m and the error is 6.72%, which is consistent with actual field measurement result.