Abstract: The water damage of the top of Jurassic deep buried coal seam in Hujiert Mining Area threatens the mine safety. It was particularly important to study the height of water flowing fractured zone in overburden strata. Take the Bayangaole Coal Mine as an example, through theoretical calculation, numerical simulation, simulation of similar materials, field measurement and other means, we analyzed and studied the height of 3^-1 coal seam roof water flowing fractured zone in the first mining face. The results showed that there were some defects in the theoretical calculation and methods, which were not suitable for the height prediction of water flowing fractured zone in this coal mine. The method of single loop double capsule sealing water pressure test had good effect in field measurement. The results of comparative analysis, numerical simulation, similar material simulation and field measurement were basically consistent. Based on the results of the average method, it could be obtain that the development height of roof water flowing fractured zone was about 122 m in 311101 first mining face of 3^-1 coal seam of Bayangaole Coal Mine, and the mining ratio was about 23 times based on the mining height of 5.3 m, which could be used as a reference for the water prevention and control in the future mining process.