Abstract: Taking the no.117 fully mechanized top coal caving stope in Jinjitan coal mine as the research object, the paper studies the development regularity characteristics of roof overburden water conducting fractured zone, and constructs the predictive model for the maximum height of water conducting fractured zone induced by the fully-mechanized caving mining of Jurassic extra thick coal seam in Northern Shaanxi with the methods of optical fiber monitoring, post mining borehole flushing fluid leakage observation and fitting calculation. The field monitoring results show that the maximum height of the water conducting fractured zone ranges from 220.82m to 223.75m, the average ratio of the water conducting fractured zone height to the mining height is 20.21, and the calculation result of the predictive model has an average relative error of 2.96% to the measured results. The research result shows that with the advance of the no.117 stope mining, coal seam roof water conducting fractured zone develops rapidly upward; When the top boundary of the water conducting fractured zone develops to soil rock interface, the upward growth rate of water conducting fractured zone decreases rapidly, the key impermeable soil layer has a significant inhibitory effect on the development of water conducting fractured zone; When mining over about 100m, water conducting fractured zone develops to the maximum height; Due to the self-repair characteristic of Lishi loess(Q2l) after being damaged by mining, the maximum height of water conducting fractured zone decreases slightly with the continuous mining, and the development of water conducting fractured zone does not penetrate the key impermeable soil layer. The research conclusion can further provide a scientific reference for safe production and coal seam roof water rush prevention in the coal mine with extra thick coal seam mining in Northern Shaanxi.