Abstract: In order to protect the water inrush accident taking place in the Taiyuan Group during exploitation in the Yangcun Coal Mine,the existing hydrogeologcal observation holes are used to carry out spot pint-size artesian tests of the Ordovician limestone aquifer and simulate the groundwater flow field in the course of artesian tests by using the software of the GMS to obtain the hydrogeological parameters.The results of the artesian tests and numerical simulation show that the Ordovician limestone has no direct hydrodynamic connection with the water of the thirteenth and fourteenth limestone layers under natural state.It is needed to dredge the water and reduce the stress for thirteenth and fourteenth limestone layers.It is also needed to keep away from the Ordovician limestone water and deal with the headrace in times.