Abstract: The simplex ground or underground gas extraction is difficult to meet the need of safe and efficient production of coal mine, confined to the high gas content and low permeability of coal seam in Jincheng mining area.Therefore, the exploration of "ground fracturing+underground extraction" tridimensional extraction model has been carried out.In order to understand the reasonable connection between ground and underground gas extraction engineering in space and time, the ground fracturing was numerical simulated firstly by discrete element software, the rule and calculation formula of fracture propagation were obtained, and its applicability has been verified by the experiments in Zhaozhuang Coal Mine, which provides a quantitative method for predicting the influence scope of fracturing. Through field test and investigation in Zhaozhuang and Chengzhuang Coal Mines, the reasonable time-space parameters of ground fracturing and underground gas extraction in low permeability coal seam in Jincheng mining area were put forward.The quantitative determination method of reasonable temporal-spatial relationship was proposed, it can give full play to the combined extraction advantages of "ground fracturing+underground extraction" mode and provide technical support for the promotion and application of similar conditions in mining areas across the country.