Abstract: In order to study the development height of water flowing fractured zone in No.4 coal seam of Yadian Coal Mine. Firstly, the failure law of strata, stress distribution law and the development height of water flowing fractured zone were numerical simulated by using UDEC. Secondly, the height of water flowing fractured zone of 47 boreholes in No.4 coal seam was determined by theoretical calculation method and engineering analogy method.The range and depth of the Luohe formation aquifer (K1l) when water flowing fractured zone broke above the coal seam were obtained by comparison according to the field data. Finally, under the comprehensive consideration of numerical simulation, theoretical calculation, engineering analogy and field measurement, it was concluded that the average height of water flowing fractured zone of No. 4 coal seam was from 205 m to 214 m, and the maximum crack in mining height was 20.The results show that most of water flowing fractured zone in No.4 coal seam have broken through the bottom boundary of Luohe formation aquifer, and effective measures should be taken to ensure safe mining during normal production.