It is a very effective way to reduce the shortage of regional water resources by constructing emergency karst groundwater sources. However, the evaluation and determination of the safety yield of Karst groundwater resources is a difficult technical problem to be solved, and conventional methods are often difficult to work effectively. In view of many good properties such as the large Karst water storage space which can be a dam-free Karst groundwater reservoir,closed boundary conditions,and the distinct seasonal characteristics of clear rainy and dry seasons in the Zihe Rivers Source Region, this paper uses the principle of “water abundance in rainy season to make up shortage in dry season” to calculate and evaluate the Karst groundwater in this area. The safety yield in this area is 21,900 m3/d. The results show that the source Region of the Zihe River is a big natural underground reservoir, which can be used rationally and effectively to develop and utilize water resources, alleviate the contradiction between water supply and demand in the region and control the decline of groundwater. The research results can provide a scientific basis for the rational development, utilization and protection of groundwater resources in the region.