Abstract: The quantitative degree of coal resources exploitation on water environment disturbance is insufficient in the coal mining area of western China. In this paper,it concludes that the spatial scale is the main factor to control the loss of groundwater by the method of groundwater dynamics analysis,which includes the caving zone,the fracture zone,the bending zone and the ground subsidence area. The method of numerical evaluation model of groundwater system is pro- posed,which is based on the boundary of the hydraulic conductivity of overlying rock,the partition of bending zone, and the re-subdivision of surface subsidence area. According to the quantitative evaluation of groundwater dynamic sys- tem disturbance in the Bulianta coal mine,the simulation results show that the loss of groundwater resources is about 1. 90×104 m3 / d due to the mining disturbance.