At Present, a large high-pressure water from Ordovician limestone has threaten deep mining of the lower group coal in Yanzhou Coal, and local large-scale coal chemical enterprises have some difficulties to meet their water need for production. To address this problem, water yield property of Ordovician limestone has been studied on the basis of hydrogeological exploration and draining test which has been done. Finite-difference method is been used to simulate drainage and pressure lowering of Ordovician limestone aquifer. And finally, a proposal on water and coal co-exploitation is put forward. The results show that: a high water pressure of deep Ordovician limestone in Yanzhou Coal can be pumped down effectively by a rational arrangement of boreholes. The maximum drawdown in the central area of Ordovician limestone aquifer can be up to 110m, and water inrush coefficient decreased significantly, which improves the safety for mining lower group coal. And at the same time, water supply for coal chemical enterprises with 43200m3/d can be satisfied, and groundwater resources can be achieved to a sustainable exploitation, which finally achieve water and coal co-exploitation of lower group coal.